Merge branch 'jc/maint-1.6.0-blank-at-eof' (early part) into jc/maint-blank-at-eof
[git/git.git] / diff.c
diff --git a/diff.c b/diff.c
index 7548966..e03b16c 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -11,6 +11,8 @@
 #include "attr.h"
 #include "run-command.h"
 #include "utf8.h"
+#include "userdiff.h"
+#include "sigchain.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
 
 static int diff_detect_rename_default;
 static int diff_rename_limit_default = 200;
+static int diff_suppress_blank_empty;
 int diff_use_color_default = -1;
+static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
 int diff_auto_refresh_index = 1;
+static int diff_mnemonic_prefix;
 
 static char diff_colors[][COLOR_MAXLEN] = {
-       "\033[m",       /* reset */
-       "",             /* PLAIN (normal) */
-       "\033[1m",      /* METAINFO (bold) */
-       "\033[36m",     /* FRAGINFO (cyan) */
-       "\033[31m",     /* OLD (red) */
-       "\033[32m",     /* NEW (green) */
-       "\033[33m",     /* COMMIT (yellow) */
-       "\033[41m",     /* WHITESPACE (red background) */
+       GIT_COLOR_RESET,
+       GIT_COLOR_NORMAL,       /* PLAIN */
+       GIT_COLOR_BOLD,         /* METAINFO */
+       GIT_COLOR_CYAN,         /* FRAGINFO */
+       GIT_COLOR_RED,          /* OLD */
+       GIT_COLOR_GREEN,        /* NEW */
+       GIT_COLOR_YELLOW,       /* COMMIT */
+       GIT_COLOR_BG_RED,       /* WHITESPACE */
 };
 
+static void diff_filespec_load_driver(struct diff_filespec *one);
+static char *run_textconv(const char *, struct diff_filespec *, size_t *);
+
 static int parse_diff_color_slot(const char *var, int ofs)
 {
        if (!strcasecmp(var+ofs, "plain"))
@@ -54,78 +62,13 @@ static int parse_diff_color_slot(const char *var, int ofs)
        die("bad config variable '%s'", var);
 }
 
-static struct ll_diff_driver {
-       const char *name;
-       struct ll_diff_driver *next;
-       const char *cmd;
-} *user_diff, **user_diff_tail;
-
-/*
- * Currently there is only "diff.<drivername>.command" variable;
- * because there are "diff.color.<slot>" variables, we are parsing
- * this in a bit convoluted way to allow low level diff driver
- * called "color".
- */
-static int parse_lldiff_command(const char *var, const char *ep, const char *value)
-{
-       const char *name;
-       int namelen;
-       struct ll_diff_driver *drv;
-
-       name = var + 5;
-       namelen = ep - name;
-       for (drv = user_diff; drv; drv = drv->next)
-               if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
-                       break;
-       if (!drv) {
-               drv = xcalloc(1, sizeof(struct ll_diff_driver));
-               drv->name = xmemdupz(name, namelen);
-               if (!user_diff_tail)
-                       user_diff_tail = &user_diff;
-               *user_diff_tail = drv;
-               user_diff_tail = &(drv->next);
-       }
-
-       return git_config_string(&(drv->cmd), var, value);
-}
-
-/*
- * 'diff.<what>.funcname' attribute can be specified in the configuration
- * to define a customized regexp to find the beginning of a function to
- * be used for hunk header lines of "diff -p" style output.
- */
-struct funcname_pattern_entry {
-       char *name;
-       char *pattern;
-       int cflags;
-};
-static struct funcname_pattern_list {
-       struct funcname_pattern_list *next;
-       struct funcname_pattern_entry e;
-} *funcname_pattern_list;
-
-static int parse_funcname_pattern(const char *var, const char *ep, const char *value, int cflags)
+static int git_config_rename(const char *var, const char *value)
 {
-       const char *name;
-       int namelen;
-       struct funcname_pattern_list *pp;
-
-       name = var + 5; /* "diff." */
-       namelen = ep - name;
-
-       for (pp = funcname_pattern_list; pp; pp = pp->next)
-               if (!strncmp(pp->e.name, name, namelen) && !pp->e.name[namelen])
-                       break;
-       if (!pp) {
-               pp = xcalloc(1, sizeof(*pp));
-               pp->e.name = xmemdupz(name, namelen);
-               pp->next = funcname_pattern_list;
-               funcname_pattern_list = pp;
-       }
-       free(pp->e.pattern);
-       pp->e.pattern = xstrdup(value);
-       pp->e.cflags = cflags;
-       return 0;
+       if (!value)
+               return DIFF_DETECT_RENAME;
+       if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
+               return  DIFF_DETECT_COPY;
+       return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 }
 
 /*
@@ -141,27 +84,21 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                return 0;
        }
        if (!strcmp(var, "diff.renames")) {
-               if (!value)
-                       diff_detect_rename_default = DIFF_DETECT_RENAME;
-               else if (!strcasecmp(value, "copies") ||
-                        !strcasecmp(value, "copy"))
-                       diff_detect_rename_default = DIFF_DETECT_COPY;
-               else if (git_config_bool(var,value))
-                       diff_detect_rename_default = DIFF_DETECT_RENAME;
+               diff_detect_rename_default = git_config_rename(var, value);
                return 0;
        }
        if (!strcmp(var, "diff.autorefreshindex")) {
                diff_auto_refresh_index = git_config_bool(var, value);
                return 0;
        }
+       if (!strcmp(var, "diff.mnemonicprefix")) {
+               diff_mnemonic_prefix = git_config_bool(var, value);
+               return 0;
+       }
        if (!strcmp(var, "diff.external"))
                return git_config_string(&external_diff_cmd_cfg, var, value);
-       if (!prefixcmp(var, "diff.")) {
-               const char *ep = strrchr(var, '.');
-
-               if (ep != var + 4 && !strcmp(ep, ".command"))
-                       return parse_lldiff_command(var, ep, value);
-       }
+       if (!strcmp(var, "diff.wordregex"))
+               return git_config_string(&diff_word_regex_cfg, var, value);
 
        return git_diff_basic_config(var, value, cb);
 }
@@ -173,6 +110,12 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
+       switch (userdiff_config(var, value)) {
+               case 0: break;
+               case -1: return -1;
+               default: return 0;
+       }
+
        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
                int slot = parse_diff_color_slot(var, 11);
                if (!value)
@@ -181,21 +124,12 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
-       if (!prefixcmp(var, "diff.")) {
-               const char *ep = strrchr(var, '.');
-               if (ep != var + 4) {
-                       if (!strcmp(ep, ".funcname")) {
-                               if (!value)
-                                       return config_error_nonbool(var);
-                               return parse_funcname_pattern(var, ep, value,
-                                       0);
-                       } else if (!strcmp(ep, ".xfuncname")) {
-                               if (!value)
-                                       return config_error_nonbool(var);
-                               return parse_funcname_pattern(var, ep, value,
-                                       REG_EXTENDED);
-                       }
-               }
+       /* like GNU diff's --suppress-blank-empty option  */
+       if (!strcmp(var, "diff.suppressblankempty") ||
+                       /* for backwards compatibility */
+                       !strcmp(var, "diff.suppress-blank-empty")) {
+               diff_suppress_blank_empty = git_config_bool(var, value);
+               return 0;
        }
 
        return git_color_default_config(var, value, cb);
@@ -205,9 +139,8 @@ static char *quote_two(const char *one, const char *two)
 {
        int need_one = quote_c_style(one, NULL, NULL, 1);
        int need_two = quote_c_style(two, NULL, NULL, 1);
-       struct strbuf res;
+       struct strbuf res = STRBUF_INIT;
 
-       strbuf_init(&res, 0);
        if (need_one + need_two) {
                strbuf_addch(&res, '"');
                quote_c_style(one, &res, NULL, 1);
@@ -244,7 +177,6 @@ static struct diff_tempfile {
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 
 struct emit_callback {
-       struct xdiff_emit_state xm;
        int color_diff;
        unsigned ws_rule;
        int blank_at_eof_in_preimage;
@@ -281,43 +213,6 @@ static int count_lines(const char *data, int size)
        return count;
 }
 
-static void print_line_count(FILE *file, int count)
-{
-       switch (count) {
-       case 0:
-               fprintf(file, "0,0");
-               break;
-       case 1:
-               fprintf(file, "1");
-               break;
-       default:
-               fprintf(file, "1,%d", count);
-               break;
-       }
-}
-
-static void copy_file_with_prefix(FILE *file,
-                                 int prefix, const char *data, int size,
-                                 const char *set, const char *reset)
-{
-       int ch, nl_just_seen = 1;
-       while (0 < size--) {
-               ch = *data++;
-               if (nl_just_seen) {
-                       fputs(set, file);
-                       putc(prefix, file);
-               }
-               if (ch == '\n') {
-                       nl_just_seen = 1;
-                       fputs(reset, file);
-               } else
-                       nl_just_seen = 0;
-               putc(ch, file);
-       }
-       if (!nl_just_seen)
-               fprintf(file, "%s\n\\ No newline at end of file\n", reset);
-}
-
 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 {
        if (!DIFF_FILE_VALID(one)) {
@@ -327,6 +222,7 @@ static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
        }
        else if (diff_populate_filespec(one, 0))
                return -1;
+
        mf->ptr = one->data;
        mf->size = one->size;
        return 0;
@@ -426,10 +322,76 @@ static void emit_add_line(const char *reset, struct emit_callback *ecbdata, cons
        }
 }
 
+static struct diff_tempfile *claim_diff_tempfile(void) {
+       int i;
+       for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
+               if (!diff_temp[i].name)
+                       return diff_temp + i;
+       die("BUG: diff is failing to clean up its tempfiles");
+}
+
+static int remove_tempfile_installed;
+
+static void remove_tempfile(void)
+{
+       int i;
+       for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
+               if (diff_temp[i].name == diff_temp[i].tmp_path)
+                       unlink_or_warn(diff_temp[i].name);
+               diff_temp[i].name = NULL;
+       }
+}
+
+static void remove_tempfile_on_signal(int signo)
+{
+       remove_tempfile();
+       sigchain_pop(signo);
+       raise(signo);
+}
+
+static void print_line_count(FILE *file, int count)
+{
+       switch (count) {
+       case 0:
+               fprintf(file, "0,0");
+               break;
+       case 1:
+               fprintf(file, "1");
+               break;
+       default:
+               fprintf(file, "1,%d", count);
+               break;
+       }
+}
+
+static void copy_file_with_prefix(FILE *file,
+                                 int prefix, const char *data, int size,
+                                 const char *set, const char *reset)
+{
+       int ch, nl_just_seen = 1;
+       while (0 < size--) {
+               ch = *data++;
+               if (nl_just_seen) {
+                       fputs(set, file);
+                       putc(prefix, file);
+               }
+               if (ch == '\n') {
+                       nl_just_seen = 1;
+                       fputs(reset, file);
+               } else
+                       nl_just_seen = 0;
+               putc(ch, file);
+       }
+       if (!nl_just_seen)
+               fprintf(file, "%s\n\\ No newline at end of file\n", reset);
+}
+
 static void emit_rewrite_diff(const char *name_a,
                              const char *name_b,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
+                             const char *textconv_one,
+                             const char *textconv_two,
                              struct diff_options *o)
 {
        int lc_a, lc_b;
@@ -441,6 +403,17 @@ static void emit_rewrite_diff(const char *name_a,
        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
        const char *reset = diff_get_color(color_diff, DIFF_RESET);
        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
+       const char *a_prefix, *b_prefix;
+       const char *data_one, *data_two;
+       size_t size_one, size_two;
+
+       if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
+               a_prefix = o->b_prefix;
+               b_prefix = o->a_prefix;
+       } else {
+               a_prefix = o->a_prefix;
+               b_prefix = o->b_prefix;
+       }
 
        name_a += (*name_a == '/');
        name_b += (*name_b == '/');
@@ -449,13 +422,32 @@ static void emit_rewrite_diff(const char *name_a,
 
        strbuf_reset(&a_name);
        strbuf_reset(&b_name);
-       quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
-       quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
+       quote_two_c_style(&a_name, a_prefix, name_a, 0);
+       quote_two_c_style(&b_name, b_prefix, name_b, 0);
 
        diff_populate_filespec(one, 0);
        diff_populate_filespec(two, 0);
-       lc_a = count_lines(one->data, one->size);
-       lc_b = count_lines(two->data, two->size);
+       if (textconv_one) {
+               data_one = run_textconv(textconv_one, one, &size_one);
+               if (!data_one)
+                       die("unable to read files to diff");
+       }
+       else {
+               data_one = one->data;
+               size_one = one->size;
+       }
+       if (textconv_two) {
+               data_two = run_textconv(textconv_two, two, &size_two);
+               if (!data_two)
+                       die("unable to read files to diff");
+       }
+       else {
+               data_two = two->data;
+               size_two = two->size;
+       }
+
+       lc_a = count_lines(data_one, size_one);
+       lc_b = count_lines(data_two, size_two);
        fprintf(o->file,
                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
                metainfo, a_name.buf, name_a_tab, reset,
@@ -465,91 +457,146 @@ static void emit_rewrite_diff(const char *name_a,
        print_line_count(o->file, lc_b);
        fprintf(o->file, " @@%s\n", reset);
        if (lc_a)
-               copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
+               copy_file_with_prefix(o->file, '-', data_one, size_one, old, reset);
        if (lc_b)
-               copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
+               copy_file_with_prefix(o->file, '+', data_two, size_two, new, reset);
 }
 
 struct diff_words_buffer {
        mmfile_t text;
        long alloc;
-       long current; /* output pointer */
-       int suppressed_newline;
+       struct diff_words_orig {
+               const char *begin, *end;
+       } *orig;
+       int orig_nr, orig_alloc;
 };
 
 static void diff_words_append(char *line, unsigned long len,
                struct diff_words_buffer *buffer)
 {
-       if (buffer->text.size + len > buffer->alloc) {
-               buffer->alloc = (buffer->text.size + len) * 3 / 2;
-               buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
-       }
+       ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
        line++;
        len--;
        memcpy(buffer->text.ptr + buffer->text.size, line, len);
        buffer->text.size += len;
+       buffer->text.ptr[buffer->text.size] = '\0';
 }
 
 struct diff_words_data {
-       struct xdiff_emit_state xm;
        struct diff_words_buffer minus, plus;
+       const char *current_plus;
        FILE *file;
+       regex_t *word_regex;
 };
 
-static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
-               int suppress_newline)
+static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 {
-       const char *ptr;
-       int eol = 0;
+       struct diff_words_data *diff_words = priv;
+       int minus_first, minus_len, plus_first, plus_len;
+       const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 
-       if (len == 0)
+       if (line[0] != '@' || parse_hunk_header(line, len,
+                       &minus_first, &minus_len, &plus_first, &plus_len))
                return;
 
-       ptr  = buffer->text.ptr + buffer->current;
-       buffer->current += len;
+       /* POSIX requires that first be decremented by one if len == 0... */
+       if (minus_len) {
+               minus_begin = diff_words->minus.orig[minus_first].begin;
+               minus_end =
+                       diff_words->minus.orig[minus_first + minus_len - 1].end;
+       } else
+               minus_begin = minus_end =
+                       diff_words->minus.orig[minus_first].end;
 
-       if (ptr[len - 1] == '\n') {
-               eol = 1;
-               len--;
+       if (plus_len) {
+               plus_begin = diff_words->plus.orig[plus_first].begin;
+               plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
+       } else
+               plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
+
+       if (diff_words->current_plus != plus_begin)
+               fwrite(diff_words->current_plus,
+                               plus_begin - diff_words->current_plus, 1,
+                               diff_words->file);
+       if (minus_begin != minus_end)
+               color_fwrite_lines(diff_words->file,
+                               diff_get_color(1, DIFF_FILE_OLD),
+                               minus_end - minus_begin, minus_begin);
+       if (plus_begin != plus_end)
+               color_fwrite_lines(diff_words->file,
+                               diff_get_color(1, DIFF_FILE_NEW),
+                               plus_end - plus_begin, plus_begin);
+
+       diff_words->current_plus = plus_end;
+}
+
+/* This function starts looking at *begin, and returns 0 iff a word was found. */
+static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
+               int *begin, int *end)
+{
+       if (word_regex && *begin < buffer->size) {
+               regmatch_t match[1];
+               if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
+                       char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
+                                       '\n', match[0].rm_eo - match[0].rm_so);
+                       *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
+                       *begin += match[0].rm_so;
+                       return *begin >= *end;
+               }
+               return -1;
        }
 
-       fputs(diff_get_color(1, color), file);
-       fwrite(ptr, len, 1, file);
-       fputs(diff_get_color(1, DIFF_RESET), file);
+       /* find the next word */
+       while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
+               (*begin)++;
+       if (*begin >= buffer->size)
+               return -1;
 
-       if (eol) {
-               if (suppress_newline)
-                       buffer->suppressed_newline = 1;
-               else
-                       putc('\n', file);
-       }
+       /* find the end of the word */
+       *end = *begin + 1;
+       while (*end < buffer->size && !isspace(buffer->ptr[*end]))
+               (*end)++;
+
+       return 0;
 }
 
-static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
+/*
+ * This function splits the words in buffer->text, stores the list with
+ * newline separator into out, and saves the offsets of the original words
+ * in buffer->orig.
+ */
+static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
+               regex_t *word_regex)
 {
-       struct diff_words_data *diff_words = priv;
+       int i, j;
+       long alloc = 0;
 
-       if (diff_words->minus.suppressed_newline) {
-               if (line[0] != '+')
-                       putc('\n', diff_words->file);
-               diff_words->minus.suppressed_newline = 0;
-       }
+       out->size = 0;
+       out->ptr = NULL;
 
-       len--;
-       switch (line[0]) {
-               case '-':
-                       print_word(diff_words->file,
-                                  &diff_words->minus, len, DIFF_FILE_OLD, 1);
-                       break;
-               case '+':
-                       print_word(diff_words->file,
-                                  &diff_words->plus, len, DIFF_FILE_NEW, 0);
-                       break;
-               case ' ':
-                       print_word(diff_words->file,
-                                  &diff_words->plus, len, DIFF_PLAIN, 0);
-                       diff_words->minus.current += len;
-                       break;
+       /* fake an empty "0th" word */
+       ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
+       buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
+       buffer->orig_nr = 1;
+
+       for (i = 0; i < buffer->text.size; i++) {
+               if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
+                       return;
+
+               /* store original boundaries */
+               ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
+                               buffer->orig_alloc);
+               buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
+               buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
+               buffer->orig_nr++;
+
+               /* store one word */
+               ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
+               memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
+               out->ptr[out->size + j - i] = '\n';
+               out->size += j - i + 1;
+
+               i = j - 1;
        }
 }
 
@@ -560,40 +607,36 @@ static void diff_words_show(struct diff_words_data *diff_words)
        xdemitconf_t xecfg;
        xdemitcb_t ecb;
        mmfile_t minus, plus;
-       int i;
 
-       memset(&xecfg, 0, sizeof(xecfg));
-       minus.size = diff_words->minus.text.size;
-       minus.ptr = xmalloc(minus.size);
-       memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
-       for (i = 0; i < minus.size; i++)
-               if (isspace(minus.ptr[i]))
-                       minus.ptr[i] = '\n';
-       diff_words->minus.current = 0;
-
-       plus.size = diff_words->plus.text.size;
-       plus.ptr = xmalloc(plus.size);
-       memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
-       for (i = 0; i < plus.size; i++)
-               if (isspace(plus.ptr[i]))
-                       plus.ptr[i] = '\n';
-       diff_words->plus.current = 0;
+       /* special case: only removal */
+       if (!diff_words->plus.text.size) {
+               color_fwrite_lines(diff_words->file,
+                       diff_get_color(1, DIFF_FILE_OLD),
+                       diff_words->minus.text.size, diff_words->minus.text.ptr);
+               diff_words->minus.text.size = 0;
+               return;
+       }
 
-       xpp.flags = XDF_NEED_MINIMAL;
-       xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
-       ecb.outf = xdiff_outf;
-       ecb.priv = diff_words;
-       diff_words->xm.consume = fn_out_diff_words_aux;
-       xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
+       diff_words->current_plus = diff_words->plus.text.ptr;
 
+       memset(&xpp, 0, sizeof(xpp));
+       memset(&xecfg, 0, sizeof(xecfg));
+       diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
+       diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
+       xpp.flags = XDF_NEED_MINIMAL;
+       /* as only the hunk header will be parsed, we need a 0-context */
+       xecfg.ctxlen = 0;
+       xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
+                     &xpp, &xecfg, &ecb);
        free(minus.ptr);
        free(plus.ptr);
+       if (diff_words->current_plus != diff_words->plus.text.ptr +
+                       diff_words->plus.text.size)
+               fwrite(diff_words->current_plus,
+                       diff_words->plus.text.ptr + diff_words->plus.text.size
+                       - diff_words->current_plus, 1,
+                       diff_words->file);
        diff_words->minus.text.size = diff_words->plus.text.size = 0;
-
-       if (diff_words->minus.suppressed_newline) {
-               putc('\n', diff_words->file);
-               diff_words->minus.suppressed_newline = 0;
-       }
 }
 
 static void free_diff_words_data(struct emit_callback *ecbdata)
@@ -605,7 +648,10 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
                        diff_words_show(ecbdata->diff_words);
 
                free (ecbdata->diff_words->minus.text.ptr);
+               free (ecbdata->diff_words->minus.orig);
                free (ecbdata->diff_words->plus.text.ptr);
+               free (ecbdata->diff_words->plus.orig);
+               free(ecbdata->diff_words->word_regex);
                free(ecbdata->diff_words);
                ecbdata->diff_words = NULL;
        }
@@ -673,6 +719,12 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
 
+       if (diff_suppress_blank_empty
+           && len == 2 && line[0] == ' ' && line[1] == '\n') {
+               line[0] = '\n';
+               len = 1;
+       }
+
        if (line[0] == '@') {
                len = sane_truncate_line(ecbdata, line, len);
                find_lno(line, ecbdata);
@@ -726,7 +778,7 @@ static char *pprint_rename(const char *a, const char *b)
 {
        const char *old = a;
        const char *new = b;
-       struct strbuf name;
+       struct strbuf name = STRBUF_INIT;
        int pfx_length, sfx_length;
        int len_a = strlen(a);
        int len_b = strlen(b);
@@ -734,7 +786,6 @@ static char *pprint_rename(const char *a, const char *b)
        int qlen_a = quote_c_style(a, NULL, NULL, 0);
        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 
-       strbuf_init(&name, 0);
        if (qlen_a || qlen_b) {
                quote_c_style(a, &name, NULL, 0);
                strbuf_addstr(&name, " => ");
@@ -791,8 +842,6 @@ static char *pprint_rename(const char *a, const char *b)
 }
 
 struct diffstat_t {
-       struct xdiff_emit_state xm;
-
        int nr;
        int alloc;
        struct diffstat_file {
@@ -855,10 +904,9 @@ static int scale_linear(int it, int width, int max_change)
 }
 
 static void show_name(FILE *file,
-                     const char *prefix, const char *name, int len,
-                     const char *reset, const char *set)
+                     const char *prefix, const char *name, int len)
 {
-       fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
+       fprintf(file, " %s%-*s |", prefix, len, name);
 }
 
 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
@@ -879,8 +927,7 @@ static void fill_print_name(struct diffstat_file *file)
                return;
 
        if (!file->is_renamed) {
-               struct strbuf buf;
-               strbuf_init(&buf, 0);
+               struct strbuf buf = STRBUF_INIT;
                if (quote_c_style(file->name, &buf, NULL, 0)) {
                        pname = strbuf_detach(&buf, NULL);
                } else {
@@ -893,9 +940,9 @@ static void fill_print_name(struct diffstat_file *file)
        file->print_name = pname;
 }
 
-static void show_stats(struct diffstat_tdata, struct diff_options *options)
+static void show_stats(struct diffstat_t *data, struct diff_options *options)
 {
-       int i, len, add, del, total, adds = 0, dels = 0;
+       int i, len, add, del, adds = 0, dels = 0;
        int max_change = 0, max_len = 0;
        int total_files = data->nr;
        int width, name_width;
@@ -973,7 +1020,7 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                }
 
                if (data->files[i]->is_binary) {
-                       show_name(options->file, prefix, name, len, reset, set);
+                       show_name(options->file, prefix, name, len);
                        fprintf(options->file, "  Bin ");
                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
                        fprintf(options->file, " -> ");
@@ -983,7 +1030,7 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                        continue;
                }
                else if (data->files[i]->is_unmerged) {
-                       show_name(options->file, prefix, name, len, reset, set);
+                       show_name(options->file, prefix, name, len);
                        fprintf(options->file, "  Unmerged\n");
                        continue;
                }
@@ -998,16 +1045,14 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                 */
                add = added;
                del = deleted;
-               total = add + del;
                adds += add;
                dels += del;
 
                if (width <= max_change) {
                        add = scale_linear(add, width, max_change);
                        del = scale_linear(del, width, max_change);
-                       total = add + del;
                }
-               show_name(options->file, prefix, name, len, reset, set);
+               show_name(options->file, prefix, name, len);
                fprintf(options->file, "%5d%s", added + deleted,
                                added + deleted ? " " : "");
                show_graph(options->file, '+', add, add_c, reset);
@@ -1015,8 +1060,8 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                fprintf(options->file, "\n");
        }
        fprintf(options->file,
-              "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
-              set, total_files, adds, dels, reset);
+              " %d files changed, %d insertions(+), %d deletions(-)\n",
+              total_files, adds, dels);
 }
 
 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
@@ -1044,7 +1089,7 @@ static void show_shortstats(struct diffstat_t* data, struct diff_options *option
               total_files, adds, dels);
 }
 
-static void show_numstat(struct diffstat_tdata, struct diff_options *options)
+static void show_numstat(struct diffstat_t *data, struct diff_options *options)
 {
        int i;
 
@@ -1187,9 +1232,13 @@ static void show_dirstat(struct diff_options *options)
                /*
                 * Original minus copied is the removed material,
                 * added is the new material.  They are both damages
-                * made to the preimage.
+                * made to the preimage. In --dirstat-by-file mode, count
+                * damaged files, not damaged lines. This is done by
+                * counting only a single damaged line per file.
                 */
                damage = (p->one->size - copied) + added;
+               if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
+                       damage = 1;
 
                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
                dir.files[dir.nr].name = name;
@@ -1222,7 +1271,6 @@ static void free_diffstat_info(struct diffstat_t *diffstat)
 }
 
 struct checkdiff_t {
-       struct xdiff_emit_state xm;
        const char *filename;
        int lineno;
        struct diff_options *o;
@@ -1390,123 +1438,61 @@ static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
        emit_binary_diff_body(file, two, one);
 }
 
-static void setup_diff_attr_check(struct git_attr_check *check)
+static void diff_filespec_load_driver(struct diff_filespec *one)
 {
-       static struct git_attr *attr_diff;
-
-       if (!attr_diff) {
-               attr_diff = git_attr("diff", 4);
-       }
-       check[0].attr = attr_diff;
+       if (!one->driver)
+               one->driver = userdiff_find_by_path(one->path);
+       if (!one->driver)
+               one->driver = userdiff_find_by_name("default");
 }
 
-static void diff_filespec_check_attr(struct diff_filespec *one)
+int diff_filespec_is_binary(struct diff_filespec *one)
 {
-       struct git_attr_check attr_diff_check;
-       int check_from_data = 0;
-
-       if (one->checked_attr)
-               return;
-
-       setup_diff_attr_check(&attr_diff_check);
-       one->is_binary = 0;
-       one->funcname_pattern_ident = NULL;
-
-       if (!git_checkattr(one->path, 1, &attr_diff_check)) {
-               const char *value;
-
-               /* binaryness */
-               value = attr_diff_check.value;
-               if (ATTR_TRUE(value))
-                       ;
-               else if (ATTR_FALSE(value))
-                       one->is_binary = 1;
-               else
-                       check_from_data = 1;
-
-               /* funcname pattern ident */
-               if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
-                       ;
-               else
-                       one->funcname_pattern_ident = value;
-       }
-
-       if (check_from_data) {
-               if (!one->data && DIFF_FILE_VALID(one))
-                       diff_populate_filespec(one, 0);
-
-               if (one->data)
-                       one->is_binary = buffer_is_binary(one->data, one->size);
+       if (one->is_binary == -1) {
+               diff_filespec_load_driver(one);
+               if (one->driver->binary != -1)
+                       one->is_binary = one->driver->binary;
+               else {
+                       if (!one->data && DIFF_FILE_VALID(one))
+                               diff_populate_filespec(one, 0);
+                       if (one->data)
+                               one->is_binary = buffer_is_binary(one->data,
+                                               one->size);
+                       if (one->is_binary == -1)
+                               one->is_binary = 0;
+               }
        }
+       return one->is_binary;
 }
 
-int diff_filespec_is_binary(struct diff_filespec *one)
+static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
 {
-       diff_filespec_check_attr(one);
-       return one->is_binary;
+       diff_filespec_load_driver(one);
+       return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
 }
 
-static const struct funcname_pattern_entry *funcname_pattern(const char *ident)
-{
-       struct funcname_pattern_list *pp;
-
-       for (pp = funcname_pattern_list; pp; pp = pp->next)
-               if (!strcmp(ident, pp->e.name))
-                       return &pp->e;
-       return NULL;
-}
-
-static const struct funcname_pattern_entry builtin_funcname_pattern[] = {
-       { "java",
-         "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
-         "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$",
-         REG_EXTENDED },
-       { "pascal",
-         "^((procedure|function|constructor|destructor|interface|"
-               "implementation|initialization|finalization)[ \t]*.*)$"
-         "|"
-         "^(.*=[ \t]*(class|record).*)$",
-         REG_EXTENDED },
-       { "bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
-         REG_EXTENDED },
-       { "tex",
-         "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
-         REG_EXTENDED },
-       { "ruby", "^[ \t]*((class|module|def)[ \t].*)$",
-         REG_EXTENDED },
-};
-
-static const struct funcname_pattern_entry *diff_funcname_pattern(struct diff_filespec *one)
+static const char *userdiff_word_regex(struct diff_filespec *one)
 {
-       const char *ident;
-       const struct funcname_pattern_entry *pe;
-       int i;
-
-       diff_filespec_check_attr(one);
-       ident = one->funcname_pattern_ident;
-
-       if (!ident)
-               /*
-                * If the config file has "funcname.default" defined, that
-                * regexp is used; otherwise NULL is returned and xemit uses
-                * the built-in default.
-                */
-               return funcname_pattern("default");
-
-       /* Look up custom "funcname.$ident" regexp from config. */
-       pe = funcname_pattern(ident);
-       if (pe)
-               return pe;
+       diff_filespec_load_driver(one);
+       return one->driver->word_regex;
+}
 
-       /*
-        * And define built-in fallback patterns here.  Note that
-        * these can be overridden by the user's config settings.
-        */
-       for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
-               if (!strcmp(ident, builtin_funcname_pattern[i].name))
-                       return &builtin_funcname_pattern[i];
+void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
+{
+       if (!options->a_prefix)
+               options->a_prefix = a;
+       if (!options->b_prefix)
+               options->b_prefix = b;
+}
 
-       return NULL;
+static const char *get_textconv(struct diff_filespec *one)
+{
+       if (!DIFF_FILE_VALID(one))
+               return NULL;
+       if (!S_ISREG(one->mode))
+               return NULL;
+       diff_filespec_load_driver(one);
+       return one->driver->textconv;
 }
 
 static void builtin_diff(const char *name_a,
@@ -1522,13 +1508,29 @@ static void builtin_diff(const char *name_a,
        char *a_one, *b_two;
        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
        const char *reset = diff_get_color_opt(o, DIFF_RESET);
+       const char *a_prefix, *b_prefix;
+       const char *textconv_one = NULL, *textconv_two = NULL;
+
+       if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+               textconv_one = get_textconv(one);
+               textconv_two = get_textconv(two);
+       }
+
+       diff_set_mnemonic_prefix(o, "a/", "b/");
+       if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+               a_prefix = o->b_prefix;
+               b_prefix = o->a_prefix;
+       } else {
+               a_prefix = o->a_prefix;
+               b_prefix = o->b_prefix;
+       }
 
        /* Never use a non-valid filename anywhere if at all possible */
        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
 
-       a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
-       b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
+       a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
+       b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
@@ -1556,8 +1558,11 @@ static void builtin_diff(const char *name_a,
                 */
                if ((one->mode ^ two->mode) & S_IFMT)
                        goto free_ab_and_return;
-               if (complete_rewrite) {
-                       emit_rewrite_diff(name_a, name_b, one, two, o);
+               if (complete_rewrite &&
+                   (textconv_one || !diff_filespec_is_binary(one)) &&
+                   (textconv_two || !diff_filespec_is_binary(two))) {
+                       emit_rewrite_diff(name_a, name_b, one, two,
+                                               textconv_one, textconv_two, o);
                        o->found_changes = 1;
                        goto free_ab_and_return;
                }
@@ -1567,7 +1572,8 @@ static void builtin_diff(const char *name_a,
                die("unable to read files to diff");
 
        if (!DIFF_OPT_TST(o, TEXT) &&
-           (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
+           ( (diff_filespec_is_binary(one) && !textconv_one) ||
+             (diff_filespec_is_binary(two) && !textconv_two) )) {
                /* Quite common confusing case */
                if (mf1.size == mf2.size &&
                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
@@ -1586,12 +1592,28 @@ static void builtin_diff(const char *name_a,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
                struct emit_callback ecbdata;
-               const struct funcname_pattern_entry *pe;
+               const struct userdiff_funcname *pe;
+
+               if (textconv_one) {
+                       size_t size;
+                       mf1.ptr = run_textconv(textconv_one, one, &size);
+                       if (!mf1.ptr)
+                               die("unable to read files to diff");
+                       mf1.size = size;
+               }
+               if (textconv_two) {
+                       size_t size;
+                       mf2.ptr = run_textconv(textconv_two, two, &size);
+                       if (!mf2.ptr)
+                               die("unable to read files to diff");
+                       mf2.size = size;
+               }
 
                pe = diff_funcname_pattern(one);
                if (!pe)
                        pe = diff_funcname_pattern(two);
 
+               memset(&xpp, 0, sizeof(xpp));
                memset(&xecfg, 0, sizeof(xecfg));
                memset(&ecbdata, 0, sizeof(ecbdata));
                ecbdata.label_path = lbl;
@@ -1603,6 +1625,7 @@ static void builtin_diff(const char *name_a,
                ecbdata.file = o->file;
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
                xecfg.ctxlen = o->context;
+               xecfg.interhunkctxlen = o->interhunkcontext;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
                if (pe)
                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
@@ -1612,17 +1635,35 @@ static void builtin_diff(const char *name_a,
                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
                else if (!prefixcmp(diffopts, "-u"))
                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
-               ecb.outf = xdiff_outf;
-               ecb.priv = &ecbdata;
-               ecbdata.xm.consume = fn_out_consume;
                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
                        ecbdata.diff_words =
                                xcalloc(1, sizeof(struct diff_words_data));
                        ecbdata.diff_words->file = o->file;
+                       if (!o->word_regex)
+                               o->word_regex = userdiff_word_regex(one);
+                       if (!o->word_regex)
+                               o->word_regex = userdiff_word_regex(two);
+                       if (!o->word_regex)
+                               o->word_regex = diff_word_regex_cfg;
+                       if (o->word_regex) {
+                               ecbdata.diff_words->word_regex = (regex_t *)
+                                       xmalloc(sizeof(regex_t));
+                               if (regcomp(ecbdata.diff_words->word_regex,
+                                               o->word_regex,
+                                               REG_EXTENDED | REG_NEWLINE))
+                                       die ("Invalid regular expression: %s",
+                                                       o->word_regex);
+                       }
                }
-               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
+                             &xpp, &xecfg, &ecb);
                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
                        free_diff_words_data(&ecbdata);
+               if (textconv_one)
+                       free(mf1.ptr);
+               if (textconv_two)
+                       free(mf2.ptr);
+               xdiff_clear_find_func(&xecfg);
        }
 
  free_ab_and_return:
@@ -1669,11 +1710,11 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
 
+               memset(&xpp, 0, sizeof(xpp));
                memset(&xecfg, 0, sizeof(xecfg));
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
-               ecb.outf = xdiff_outf;
-               ecb.priv = diffstat;
-               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
+                             &xpp, &xecfg, &ecb);
        }
 
  free_and_return:
@@ -1694,7 +1735,6 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                return;
 
        memset(&data, 0, sizeof(data));
-       data.xm.consume = checkdiff_consume;
        data.filename = name_b ? name_b : name_a;
        data.lineno = 0;
        data.o = o;
@@ -1717,12 +1757,12 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
 
+               memset(&xpp, 0, sizeof(xpp));
                memset(&xecfg, 0, sizeof(xecfg));
                xecfg.ctxlen = 1; /* at least one context line */
                xpp.flags = XDF_NEED_MINIMAL;
-               ecb.outf = xdiff_outf;
-               ecb.priv = &data;
-               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
+                             &xpp, &xecfg, &ecb);
 
                if (data.ws_rule & WS_BLANK_AT_EOF) {
                        struct emit_callback ecbdata;
@@ -1758,6 +1798,7 @@ struct diff_filespec *alloc_filespec(const char *path)
        spec->path = (char *)(spec + 1);
        memcpy(spec->path, path, namelen+1);
        spec->count = 1;
+       spec->is_binary = -1;
        return spec;
 }
 
@@ -1790,7 +1831,8 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
        struct stat st;
        int pos, len;
 
-       /* We do not read the cache ourselves here, because the
+       /*
+        * We do not read the cache ourselves here, because the
         * benchmark with my previous version that always reads cache
         * shows that it makes things worse for diff-tree comparing
         * two linux-2.6 kernel trees in an already checked out work
@@ -1814,7 +1856,7 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
         * objects however would tend to be slower as they need
         * to be individually opened and inflated.
         */
-       if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
+       if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
                return 0;
 
        len = strlen(name);
@@ -1830,6 +1872,13 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
                return 0;
 
+       /*
+        * If ce is marked as "assume unchanged", there is no
+        * guarantee that work tree matches what we are looking for.
+        */
+       if (ce->ce_flags & CE_VALID)
+               return 0;
+
        /*
         * If ce matches the file in the work tree, we can reuse it.
         */
@@ -1842,10 +1891,9 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int populate_from_stdin(struct diff_filespec *s)
 {
-       struct strbuf buf;
+       struct strbuf buf = STRBUF_INIT;
        size_t size = 0;
 
-       strbuf_init(&buf, 0);
        if (strbuf_read(&buf, 0, 0) < 0)
                return error("error while reading from stdin %s",
                                     strerror(errno));
@@ -1897,7 +1945,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 
        if (!s->sha1_valid ||
            reuse_worktree_file(s->path, s->sha1, 0)) {
-               struct strbuf buf;
+               struct strbuf buf = STRBUF_INIT;
                struct stat st;
                int fd;
 
@@ -1917,19 +1965,18 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                s->size = xsize_t(st.st_size);
                if (!s->size)
                        goto empty;
-               if (size_only)
-                       return 0;
                if (S_ISLNK(st.st_mode)) {
-                       int ret;
-                       s->data = xmalloc(s->size);
-                       s->should_free = 1;
-                       ret = readlink(s->path, s->data, s->size);
-                       if (ret < 0) {
-                               free(s->data);
+                       struct strbuf sb = STRBUF_INIT;
+
+                       if (strbuf_readlink(&sb, s->path, s->size))
                                goto err_empty;
-                       }
+                       s->size = sb.len;
+                       s->data = strbuf_detach(&sb, NULL);
+                       s->should_free = 1;
                        return 0;
                }
+               if (size_only)
+                       return 0;
                fd = open(s->path, O_RDONLY);
                if (fd < 0)
                        goto err_empty;
@@ -1940,7 +1987,6 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                /*
                 * Convert from working tree format to canonical git format
                 */
-               strbuf_init(&buf, 0);
                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
                        size_t size = 0;
                        munmap(s->data, s->size);
@@ -1982,30 +2028,48 @@ void diff_free_filespec_data(struct diff_filespec *s)
        s->cnt_data = NULL;
 }
 
-static void prep_temp_blob(struct diff_tempfile *temp,
+static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
                           void *blob,
                           unsigned long size,
                           const unsigned char *sha1,
                           int mode)
 {
        int fd;
+       struct strbuf buf = STRBUF_INIT;
+       struct strbuf template = STRBUF_INIT;
+       char *path_dup = xstrdup(path);
+       const char *base = basename(path_dup);
+
+       /* Generate "XXXXXX_basename.ext" */
+       strbuf_addstr(&template, "XXXXXX_");
+       strbuf_addstr(&template, base);
 
-       fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
+       fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
+                       strlen(base) + 1);
        if (fd < 0)
-               die("unable to create temp-file: %s", strerror(errno));
+               die_errno("unable to create temp-file");
+       if (convert_to_working_tree(path,
+                       (const char *)blob, (size_t)size, &buf)) {
+               blob = buf.buf;
+               size = buf.len;
+       }
        if (write_in_full(fd, blob, size) != size)
-               die("unable to write temp-file");
+               die_errno("unable to write temp-file");
        close(fd);
        temp->name = temp->tmp_path;
        strcpy(temp->hex, sha1_to_hex(sha1));
        temp->hex[40] = 0;
        sprintf(temp->mode, "%06o", mode);
+       strbuf_release(&buf);
+       strbuf_release(&template);
+       free(path_dup);
 }
 
-static void prepare_temp_file(const char *name,
-                             struct diff_tempfile *temp,
-                             struct diff_filespec *one)
+static struct diff_tempfile *prepare_temp_file(const char *name,
+               struct diff_filespec *one)
 {
+       struct diff_tempfile *temp = claim_diff_tempfile();
+
        if (!DIFF_FILE_VALID(one)) {
        not_a_valid_file:
                /* A '-' entry produces this for file-2, and
@@ -2014,7 +2078,13 @@ static void prepare_temp_file(const char *name,
                temp->name = "/dev/null";
                strcpy(temp->hex, ".");
                strcpy(temp->mode, ".");
-               return;
+               return temp;
+       }
+
+       if (!remove_tempfile_installed) {
+               atexit(remove_tempfile);
+               sigchain_push_common(remove_tempfile_on_signal);
+               remove_tempfile_installed = 1;
        }
 
        if (!one->sha1_valid ||
@@ -2023,22 +2093,18 @@ static void prepare_temp_file(const char *name,
                if (lstat(name, &st) < 0) {
                        if (errno == ENOENT)
                                goto not_a_valid_file;
-                       die("stat(%s): %s", name, strerror(errno));
+                       die_errno("stat(%s)", name);
                }
                if (S_ISLNK(st.st_mode)) {
-                       int ret;
-                       char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
-                       size_t sz = xsize_t(st.st_size);
-                       if (sizeof(buf) <= st.st_size)
-                               die("symlink too long: %s", name);
-                       ret = readlink(name, buf, sz);
-                       if (ret < 0)
-                               die("readlink(%s)", name);
-                       prep_temp_blob(temp, buf, sz,
+                       struct strbuf sb = STRBUF_INIT;
+                       if (strbuf_readlink(&sb, name, st.st_size) < 0)
+                               die_errno("readlink(%s)", name);
+                       prep_temp_blob(name, temp, sb.buf, sb.len,
                                       (one->sha1_valid ?
                                        one->sha1 : null_sha1),
                                       (one->sha1_valid ?
                                        one->mode : S_IFLNK));
+                       strbuf_release(&sb);
                }
                else {
                        /* we can borrow from the file in the work tree */
@@ -2055,32 +2121,15 @@ static void prepare_temp_file(const char *name,
                         */
                        sprintf(temp->mode, "%06o", one->mode);
                }
-               return;
+               return temp;
        }
        else {
                if (diff_populate_filespec(one, 0))
                        die("cannot read data blob for %s", one->path);
-               prep_temp_blob(temp, one->data, one->size,
+               prep_temp_blob(name, temp, one->data, one->size,
                               one->sha1, one->mode);
        }
-}
-
-static void remove_tempfile(void)
-{
-       int i;
-
-       for (i = 0; i < 2; i++)
-               if (diff_temp[i].name == diff_temp[i].tmp_path) {
-                       unlink(diff_temp[i].name);
-                       diff_temp[i].name = NULL;
-               }
-}
-
-static void remove_tempfile_on_signal(int signo)
-{
-       remove_tempfile();
-       signal(SIGINT, SIG_DFL);
-       raise(signo);
+       return temp;
 }
 
 /* An external diff command takes:
@@ -2098,34 +2147,22 @@ static void run_external_diff(const char *pgm,
                              int complete_rewrite)
 {
        const char *spawn_arg[10];
-       struct diff_tempfile *temp = diff_temp;
        int retval;
-       static int atexit_asked = 0;
-       const char *othername;
        const char **arg = &spawn_arg[0];
 
-       othername = (other? other : name);
-       if (one && two) {
-               prepare_temp_file(name, &temp[0], one);
-               prepare_temp_file(othername, &temp[1], two);
-               if (! atexit_asked &&
-                   (temp[0].name == temp[0].tmp_path ||
-                    temp[1].name == temp[1].tmp_path)) {
-                       atexit_asked = 1;
-                       atexit(remove_tempfile);
-               }
-               signal(SIGINT, remove_tempfile_on_signal);
-       }
-
        if (one && two) {
+               struct diff_tempfile *temp_one, *temp_two;
+               const char *othername = (other ? other : name);
+               temp_one = prepare_temp_file(name, one);
+               temp_two = prepare_temp_file(othername, two);
                *arg++ = pgm;
                *arg++ = name;
-               *arg++ = temp[0].name;
-               *arg++ = temp[0].hex;
-               *arg++ = temp[0].mode;
-               *arg++ = temp[1].name;
-               *arg++ = temp[1].hex;
-               *arg++ = temp[1].mode;
+               *arg++ = temp_one->name;
+               *arg++ = temp_one->hex;
+               *arg++ = temp_one->mode;
+               *arg++ = temp_two->name;
+               *arg++ = temp_two->hex;
+               *arg++ = temp_two->mode;
                if (other) {
                        *arg++ = other;
                        *arg++ = xfrm_msg;
@@ -2144,29 +2181,6 @@ static void run_external_diff(const char *pgm,
        }
 }
 
-static const char *external_diff_attr(const char *name)
-{
-       struct git_attr_check attr_diff_check;
-
-       if (!name)
-               return NULL;
-
-       setup_diff_attr_check(&attr_diff_check);
-       if (!git_checkattr(name, 1, &attr_diff_check)) {
-               const char *value = attr_diff_check.value;
-               if (!ATTR_TRUE(value) &&
-                   !ATTR_FALSE(value) &&
-                   !ATTR_UNSET(value)) {
-                       struct ll_diff_driver *drv;
-
-                       for (drv = user_diff; drv; drv = drv->next)
-                               if (!strcmp(drv->name, value))
-                                       return drv->cmd;
-               }
-       }
-       return NULL;
-}
-
 static int similarity_index(struct diff_filepair *p)
 {
        return p->score * 100 / MAX_SCORE;
@@ -2250,9 +2264,9 @@ static void run_diff_cmd(const char *pgm,
        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
                pgm = NULL;
        else {
-               const char *cmd = external_diff_attr(attr_path);
-               if (cmd)
-                       pgm = cmd;
+               struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
+               if (drv && drv->external)
+                       pgm = drv->external;
        }
 
        if (pgm) {
@@ -2277,9 +2291,9 @@ static void diff_fill_sha1_info(struct diff_filespec *one)
                                return;
                        }
                        if (lstat(one->path, &st) < 0)
-                               die("stat %s", one->path);
+                               die_errno("stat '%s'", one->path);
                        if (index_path(one->sha1, one->path, &st, 0))
-                               die("cannot hash %s\n", one->path);
+                               die("cannot hash %s", one->path);
                }
        }
        else
@@ -2406,19 +2420,18 @@ void diff_setup(struct diff_options *options)
        options->break_opt = -1;
        options->rename_limit = -1;
        options->dirstat_percent = 3;
-       DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
        options->context = 3;
 
        options->change = diff_change;
        options->add_remove = diff_addremove;
        if (diff_use_color_default > 0)
                DIFF_OPT_SET(options, COLOR_DIFF);
-       else
-               DIFF_OPT_CLR(options, COLOR_DIFF);
        options->detect_rename = diff_detect_rename_default;
 
-       options->a_prefix = "a/";
-       options->b_prefix = "b/";
+       if (!diff_mnemonic_prefix) {
+               options->a_prefix = "a/";
+               options->b_prefix = "b/";
+       }
 }
 
 int diff_setup_done(struct diff_options *options)
@@ -2575,6 +2588,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--cumulative")) {
                options->output_format |= DIFF_FORMAT_DIRSTAT;
                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
+       } else if (opt_arg(arg, 0, "dirstat-by-file",
+                          &options->dirstat_percent)) {
+               options->output_format |= DIFF_FORMAT_DIRSTAT;
+               DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
        }
        else if (!strcmp(arg, "--check"))
                options->output_format |= DIFF_FORMAT_CHECKDIFF;
@@ -2644,11 +2661,13 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 
        /* xdiff options */
        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
-               options->xdl_opts |= XDF_IGNORE_WHITESPACE;
+               DIFF_XDL_SET(options, IGNORE_WHITESPACE);
        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
-               options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
+               DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
        else if (!strcmp(arg, "--ignore-space-at-eol"))
-               options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
+               DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
+       else if (!strcmp(arg, "--patience"))
+               DIFF_XDL_SET(options, PATIENCE_DIFF);
 
        /* flags options */
        else if (!strcmp(arg, "--binary")) {
@@ -2669,8 +2688,15 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_SET(options, COLOR_DIFF);
        else if (!strcmp(arg, "--no-color"))
                DIFF_OPT_CLR(options, COLOR_DIFF);
-       else if (!strcmp(arg, "--color-words"))
-               options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
+       else if (!strcmp(arg, "--color-words")) {
+               DIFF_OPT_SET(options, COLOR_DIFF);
+               DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
+       }
+       else if (!prefixcmp(arg, "--color-words=")) {
+               DIFF_OPT_SET(options, COLOR_DIFF);
+               DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
+               options->word_regex = arg + 14;
+       }
        else if (!strcmp(arg, "--exit-code"))
                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
        else if (!strcmp(arg, "--quiet"))
@@ -2679,6 +2705,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
        else if (!strcmp(arg, "--no-ext-diff"))
                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
+       else if (!strcmp(arg, "--textconv"))
+               DIFF_OPT_SET(options, ALLOW_TEXTCONV);
+       else if (!strcmp(arg, "--no-textconv"))
+               DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
        else if (!strcmp(arg, "--ignore-submodules"))
                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
 
@@ -2712,6 +2742,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->b_prefix = arg + 13;
        else if (!strcmp(arg, "--no-prefix"))
                options->a_prefix = options->b_prefix = "";
+       else if (opt_arg(arg, '\0', "inter-hunk-context",
+                        &options->interhunkcontext))
+               ;
        else if (!prefixcmp(arg, "--output=")) {
                options->file = fopen(arg + strlen("--output="), "w");
                options->close_file = 1;
@@ -3131,8 +3164,7 @@ static void diff_summary(FILE *file, struct diff_filepair *p)
 }
 
 struct patch_id_t {
-       struct xdiff_emit_state xm;
-       SHA_CTX *ctx;
+       git_SHA_CTX *ctx;
        int patchlen;
 };
 
@@ -3160,7 +3192,7 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
 
        new_len = remove_space(line, len);
 
-       SHA1_Update(data->ctx, line, new_len);
+       git_SHA1_Update(data->ctx, line, new_len);
        data->patchlen += new_len;
 }
 
@@ -3169,14 +3201,13 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
-       SHA_CTX ctx;
+       git_SHA_CTX ctx;
        struct patch_id_t data;
        char buffer[PATH_MAX * 4 + 20];
 
-       SHA1_Init(&ctx);
+       git_SHA1_Init(&ctx);
        memset(&data, 0, sizeof(struct patch_id_t));
        data.ctx = &ctx;
-       data.xm.consume = patch_id_consume;
 
        for (i = 0; i < q->nr; i++) {
                xpparam_t xpp;
@@ -3186,6 +3217,7 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                struct diff_filepair *p = q->queue[i];
                int len1, len2;
 
+               memset(&xpp, 0, sizeof(xpp));
                memset(&xecfg, 0, sizeof(xecfg));
                if (p->status == 0)
                        return error("internal diff status error");
@@ -3236,17 +3268,16 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                                        len2, p->two->path,
                                        len1, p->one->path,
                                        len2, p->two->path);
-               SHA1_Update(&ctx, buffer, len1);
+               git_SHA1_Update(&ctx, buffer, len1);
 
                xpp.flags = XDF_NEED_MINIMAL;
                xecfg.ctxlen = 3;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
-               ecb.outf = xdiff_outf;
-               ecb.priv = &data;
-               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
+                             &xpp, &xecfg, &ecb);
        }
 
-       SHA1_Final(sha1, &ctx);
+       git_SHA1_Final(sha1, &ctx);
        return 0;
 }
 
@@ -3320,7 +3351,6 @@ void diff_flush(struct diff_options *options)
                struct diffstat_t diffstat;
 
                memset(&diffstat, 0, sizeof(struct diffstat_t));
-               diffstat.xm.consume = diffstat_consume;
                for (i = 0; i < q->nr; i++) {
                        struct diff_filepair *p = q->queue[i];
                        if (check_pair_status(p))
@@ -3617,3 +3647,33 @@ void diff_unmerge(struct diff_options *options,
        fill_filespec(one, sha1, mode);
        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
 }
+
+static char *run_textconv(const char *pgm, struct diff_filespec *spec,
+               size_t *outsize)
+{
+       struct diff_tempfile *temp;
+       const char *argv[3];
+       const char **arg = argv;
+       struct child_process child;
+       struct strbuf buf = STRBUF_INIT;
+
+       temp = prepare_temp_file(spec->path, spec);
+       *arg++ = pgm;
+       *arg++ = temp->name;
+       *arg = NULL;
+
+       memset(&child, 0, sizeof(child));
+       child.argv = argv;
+       child.out = -1;
+       if (start_command(&child) != 0 ||
+           strbuf_read(&buf, child.out, 0) < 0 ||
+           finish_command(&child) != 0) {
+               strbuf_release(&buf);
+               remove_tempfile();
+               error("error running textconv command '%s'", pgm);
+               return NULL;
+       }
+       remove_tempfile();
+
+       return strbuf_detach(&buf, outsize);
+}