Merge branch 'jc/maint-1.6.0-keep-pack' into maint-1.6.1
[git/git.git] / diff.c
diff --git a/diff.c b/diff.c
index a34d26c..387d19f 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -11,6 +11,7 @@
 #include "attr.h"
 #include "run-command.h"
 #include "utf8.h"
 #include "attr.h"
 #include "run-command.h"
 #include "utf8.h"
+#include "userdiff.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
 
 #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_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 *external_diff_cmd_cfg;
 int diff_auto_refresh_index = 1;
 int diff_use_color_default = -1;
 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 */
 
 static char diff_colors[][COLOR_MAXLEN] = {
        "\033[m",       /* reset */
@@ -35,6 +38,9 @@ static char diff_colors[][COLOR_MAXLEN] = {
        "\033[41m",     /* WHITESPACE (red background) */
 };
 
        "\033[41m",     /* WHITESPACE (red background) */
 };
 
+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"))
 static int parse_diff_color_slot(const char *var, int ofs)
 {
        if (!strcasecmp(var+ofs, "plain"))
@@ -54,80 +60,6 @@ static int parse_diff_color_slot(const char *var, int ofs)
        die("bad config variable '%s'", var);
 }
 
        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)
-{
-       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;
-}
-
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
@@ -154,14 +86,12 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                diff_auto_refresh_index = git_config_bool(var, value);
                return 0;
        }
                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 (!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);
-       }
 
        return git_diff_basic_config(var, value, cb);
 }
 
        return git_diff_basic_config(var, value, cb);
 }
@@ -173,6 +103,12 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
                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)
        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
                int slot = parse_diff_color_slot(var, 11);
                if (!value)
@@ -181,21 +117,12 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
                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);
        }
 
        return git_color_default_config(var, value, cb);
@@ -205,9 +132,8 @@ 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);
 {
        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);
        if (need_one + need_two) {
                strbuf_addch(&res, '"');
                quote_c_style(one, &res, NULL, 1);
@@ -305,6 +231,8 @@ static void emit_rewrite_diff(const char *name_a,
                              const char *name_b,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
                              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;
                              struct diff_options *o)
 {
        int lc_a, lc_b;
@@ -316,6 +244,17 @@ 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 *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 == '/');
 
        name_a += (*name_a == '/');
        name_b += (*name_b == '/');
@@ -324,13 +263,32 @@ static void emit_rewrite_diff(const char *name_a,
 
        strbuf_reset(&a_name);
        strbuf_reset(&b_name);
 
        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);
 
        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,
        fprintf(o->file,
                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
                metainfo, a_name.buf, name_a_tab, reset,
@@ -340,9 +298,9 @@ 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)
        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)
        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);
 }
 
 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 }
 
 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
@@ -354,6 +312,7 @@ static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
        }
        else if (diff_populate_filespec(one, 0))
                return -1;
        }
        else if (diff_populate_filespec(one, 0))
                return -1;
+
        mf->ptr = one->data;
        mf->size = one->size;
        return 0;
        mf->ptr = one->data;
        mf->size = one->size;
        return 0;
@@ -380,7 +339,6 @@ static void diff_words_append(char *line, unsigned long len,
 }
 
 struct diff_words_data {
 }
 
 struct diff_words_data {
-       struct xdiff_emit_state xm;
        struct diff_words_buffer minus, plus;
        FILE *file;
 };
        struct diff_words_buffer minus, plus;
        FILE *file;
 };
@@ -451,6 +409,7 @@ static void diff_words_show(struct diff_words_data *diff_words)
        mmfile_t minus, plus;
        int i;
 
        mmfile_t minus, plus;
        int i;
 
+       memset(&xpp, 0, sizeof(xpp));
        memset(&xecfg, 0, sizeof(xecfg));
        minus.size = diff_words->minus.text.size;
        minus.ptr = xmalloc(minus.size);
        memset(&xecfg, 0, sizeof(xecfg));
        minus.size = diff_words->minus.text.size;
        minus.ptr = xmalloc(minus.size);
@@ -470,11 +429,8 @@ static void diff_words_show(struct diff_words_data *diff_words)
 
        xpp.flags = XDF_NEED_MINIMAL;
        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 
        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);
-
+       xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
+                     &xpp, &xecfg, &ecb);
        free(minus.ptr);
        free(plus.ptr);
        diff_words->minus.text.size = diff_words->plus.text.size = 0;
        free(minus.ptr);
        free(plus.ptr);
        diff_words->minus.text.size = diff_words->plus.text.size = 0;
@@ -488,7 +444,6 @@ static void diff_words_show(struct diff_words_data *diff_words)
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 
 struct emit_callback {
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 
 struct emit_callback {
-       struct xdiff_emit_state xm;
        int nparents, color_diff;
        unsigned ws_rule;
        sane_truncate_fn truncate;
        int nparents, color_diff;
        unsigned ws_rule;
        sane_truncate_fn truncate;
@@ -598,6 +553,12 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
 
                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;
+       }
+
        /* This is not really necessary for now because
         * this codepath only deals with two-way diffs.
         */
        /* This is not really necessary for now because
         * this codepath only deals with two-way diffs.
         */
@@ -661,7 +622,7 @@ static char *pprint_rename(const char *a, const char *b)
 {
        const char *old = a;
        const char *new = 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);
        int pfx_length, sfx_length;
        int len_a = strlen(a);
        int len_b = strlen(b);
@@ -669,7 +630,6 @@ 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);
 
        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, " => ");
        if (qlen_a || qlen_b) {
                quote_c_style(a, &name, NULL, 0);
                strbuf_addstr(&name, " => ");
@@ -726,8 +686,6 @@ static char *pprint_rename(const char *a, const char *b)
 }
 
 struct diffstat_t {
 }
 
 struct diffstat_t {
-       struct xdiff_emit_state xm;
-
        int nr;
        int alloc;
        struct diffstat_file {
        int nr;
        int alloc;
        struct diffstat_file {
@@ -814,8 +772,7 @@ static void fill_print_name(struct diffstat_file *file)
                return;
 
        if (!file->is_renamed) {
                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 {
                if (quote_c_style(file->name, &buf, NULL, 0)) {
                        pname = strbuf_detach(&buf, NULL);
                } else {
@@ -1122,9 +1079,13 @@ static void show_dirstat(struct diff_options *options)
                /*
                 * Original minus copied is the removed material,
                 * added is the new material.  They are both damages
                /*
                 * 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;
                 */
                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;
 
                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
                dir.files[dir.nr].name = name;
@@ -1157,7 +1118,6 @@ static void free_diffstat_info(struct diffstat_t *diffstat)
 }
 
 struct checkdiff_t {
 }
 
 struct checkdiff_t {
-       struct xdiff_emit_state xm;
        const char *filename;
        int lineno;
        struct diff_options *o;
        const char *filename;
        int lineno;
        struct diff_options *o;
@@ -1332,123 +1292,55 @@ static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
        emit_binary_diff_body(file, two, one);
 }
 
        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)
+void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
 {
 {
-       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;
-
-       /*
-        * 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];
+       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,
 }
 
 static void builtin_diff(const char *name_a,
@@ -1464,13 +1356,29 @@ 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);
        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;
 
 
        /* 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);
        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);
@@ -1498,8 +1406,11 @@ static void builtin_diff(const char *name_a,
                 */
                if ((one->mode ^ two->mode) & S_IFMT)
                        goto free_ab_and_return;
                 */
                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;
                }
                        o->found_changes = 1;
                        goto free_ab_and_return;
                }
@@ -1509,7 +1420,8 @@ static void builtin_diff(const char *name_a,
                die("unable to read files to diff");
 
        if (!DIFF_OPT_TST(o, TEXT) &&
                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))
                /* Quite common confusing case */
                if (mf1.size == mf2.size &&
                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
@@ -1528,12 +1440,28 @@ static void builtin_diff(const char *name_a,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
                struct emit_callback ecbdata;
                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);
 
 
                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;
                memset(&xecfg, 0, sizeof(xecfg));
                memset(&ecbdata, 0, sizeof(ecbdata));
                ecbdata.label_path = lbl;
@@ -1552,17 +1480,19 @@ 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);
                        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 (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
                        ecbdata.diff_words =
                                xcalloc(1, sizeof(struct diff_words_data));
                        ecbdata.diff_words->file = o->file;
                }
-               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 (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
                        free_diff_words_data(&ecbdata);
+               if (textconv_one)
+                       free(mf1.ptr);
+               if (textconv_two)
+                       free(mf2.ptr);
        }
 
  free_ab_and_return:
        }
 
  free_ab_and_return:
@@ -1609,11 +1539,11 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
 
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
 
+               memset(&xpp, 0, sizeof(xpp));
                memset(&xecfg, 0, sizeof(xecfg));
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
                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:
        }
 
  free_and_return:
@@ -1634,7 +1564,6 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                return;
 
        memset(&data, 0, sizeof(data));
                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;
        data.filename = name_b ? name_b : name_a;
        data.lineno = 0;
        data.o = o;
@@ -1657,12 +1586,12 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                xdemitconf_t xecfg;
                xdemitcb_t ecb;
 
                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;
                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_TRAILING_SPACE) &&
                    data.trailing_blanks_start) {
 
                if ((data.ws_rule & WS_TRAILING_SPACE) &&
                    data.trailing_blanks_start) {
@@ -1687,6 +1616,7 @@ struct diff_filespec *alloc_filespec(const char *path)
        spec->path = (char *)(spec + 1);
        memcpy(spec->path, path, namelen+1);
        spec->count = 1;
        spec->path = (char *)(spec + 1);
        memcpy(spec->path, path, namelen+1);
        spec->count = 1;
+       spec->is_binary = -1;
        return spec;
 }
 
        return spec;
 }
 
@@ -1719,7 +1649,8 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
        struct stat st;
        int pos, len;
 
        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
         * 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
@@ -1759,6 +1690,13 @@ 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 (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.
         */
        /*
         * If ce matches the file in the work tree, we can reuse it.
         */
@@ -1771,10 +1709,9 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int populate_from_stdin(struct diff_filespec *s)
 {
 
 static int populate_from_stdin(struct diff_filespec *s)
 {
-       struct strbuf buf;
+       struct strbuf buf = STRBUF_INIT;
        size_t size = 0;
 
        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));
        if (strbuf_read(&buf, 0, 0) < 0)
                return error("error while reading from stdin %s",
                                     strerror(errno));
@@ -1826,7 +1763,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
 
        if (!s->sha1_valid ||
            reuse_worktree_file(s->path, s->sha1, 0)) {
 
        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;
 
                struct stat st;
                int fd;
 
@@ -1846,19 +1783,18 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                s->size = xsize_t(st.st_size);
                if (!s->size)
                        goto empty;
                s->size = xsize_t(st.st_size);
                if (!s->size)
                        goto empty;
-               if (size_only)
-                       return 0;
                if (S_ISLNK(st.st_mode)) {
                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;
                                goto err_empty;
-                       }
+                       s->size = sb.len;
+                       s->data = strbuf_detach(&sb, NULL);
+                       s->should_free = 1;
                        return 0;
                }
                        return 0;
                }
+               if (size_only)
+                       return 0;
                fd = open(s->path, O_RDONLY);
                if (fd < 0)
                        goto err_empty;
                fd = open(s->path, O_RDONLY);
                if (fd < 0)
                        goto err_empty;
@@ -1869,7 +1805,6 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                /*
                 * Convert from working tree format to canonical git format
                 */
                /*
                 * 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);
                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
                        size_t size = 0;
                        munmap(s->data, s->size);
@@ -1957,13 +1892,12 @@ static void prepare_temp_file(const char *name,
                if (S_ISLNK(st.st_mode)) {
                        int ret;
                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
                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);
+                       ret = readlink(name, buf, sizeof(buf));
                        if (ret < 0)
                                die("readlink(%s)", name);
                        if (ret < 0)
                                die("readlink(%s)", name);
-                       prep_temp_blob(temp, buf, sz,
+                       if (ret == sizeof(buf))
+                               die("symlink too long: %s", name);
+                       prep_temp_blob(temp, buf, ret,
                                       (one->sha1_valid ?
                                        one->sha1 : null_sha1),
                                       (one->sha1_valid ?
                                       (one->sha1_valid ?
                                        one->sha1 : null_sha1),
                                       (one->sha1_valid ?
@@ -2073,27 +2007,66 @@ static void run_external_diff(const char *pgm,
        }
 }
 
        }
 }
 
-static const char *external_diff_attr(const char *name)
+static int similarity_index(struct diff_filepair *p)
 {
 {
-       struct git_attr_check attr_diff_check;
+       return p->score * 100 / MAX_SCORE;
+}
 
 
-       if (!name)
-               return NULL;
+static void fill_metainfo(struct strbuf *msg,
+                         const char *name,
+                         const char *other,
+                         struct diff_filespec *one,
+                         struct diff_filespec *two,
+                         struct diff_options *o,
+                         struct diff_filepair *p)
+{
+       strbuf_init(msg, PATH_MAX * 2 + 300);
+       switch (p->status) {
+       case DIFF_STATUS_COPIED:
+               strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
+               strbuf_addstr(msg, "\ncopy from ");
+               quote_c_style(name, msg, NULL, 0);
+               strbuf_addstr(msg, "\ncopy to ");
+               quote_c_style(other, msg, NULL, 0);
+               strbuf_addch(msg, '\n');
+               break;
+       case DIFF_STATUS_RENAMED:
+               strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
+               strbuf_addstr(msg, "\nrename from ");
+               quote_c_style(name, msg, NULL, 0);
+               strbuf_addstr(msg, "\nrename to ");
+               quote_c_style(other, msg, NULL, 0);
+               strbuf_addch(msg, '\n');
+               break;
+       case DIFF_STATUS_MODIFIED:
+               if (p->score) {
+                       strbuf_addf(msg, "dissimilarity index %d%%\n",
+                                   similarity_index(p));
+                       break;
+               }
+               /* fallthru */
+       default:
+               /* nothing */
+               ;
+       }
+       if (one && two && hashcmp(one->sha1, two->sha1)) {
+               int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 
 
-       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;
+               if (DIFF_OPT_TST(o, BINARY)) {
+                       mmfile_t mf;
+                       if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
+                           (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
+                               abbrev = 40;
                }
                }
+               strbuf_addf(msg, "index %.*s..%.*s",
+                           abbrev, sha1_to_hex(one->sha1),
+                           abbrev, sha1_to_hex(two->sha1));
+               if (one->mode == two->mode)
+                       strbuf_addf(msg, " %06o", one->mode);
+               strbuf_addch(msg, '\n');
        }
        }
-       return NULL;
+       if (msg->len)
+               strbuf_setlen(msg, msg->len - 1);
 }
 
 static void run_diff_cmd(const char *pgm,
 }
 
 static void run_diff_cmd(const char *pgm,
@@ -2102,16 +2075,24 @@ static void run_diff_cmd(const char *pgm,
                         const char *attr_path,
                         struct diff_filespec *one,
                         struct diff_filespec *two,
                         const char *attr_path,
                         struct diff_filespec *one,
                         struct diff_filespec *two,
-                        const char *xfrm_msg,
+                        struct strbuf *msg,
                         struct diff_options *o,
                         struct diff_options *o,
-                        int complete_rewrite)
+                        struct diff_filepair *p)
 {
 {
+       const char *xfrm_msg = NULL;
+       int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
+
+       if (msg) {
+               fill_metainfo(msg, name, other, one, two, o, p);
+               xfrm_msg = msg->len ? msg->buf : NULL;
+       }
+
        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
                pgm = NULL;
        else {
        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) {
        }
 
        if (pgm) {
@@ -2145,11 +2126,6 @@ static void diff_fill_sha1_info(struct diff_filespec *one)
                hashclr(one->sha1);
 }
 
                hashclr(one->sha1);
 }
 
-static int similarity_index(struct diff_filepair *p)
-{
-       return p->score * 100 / MAX_SCORE;
-}
-
 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
 {
        /* Strip the prefix but do not molest /dev/null and absolute paths */
 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
 {
        /* Strip the prefix but do not molest /dev/null and absolute paths */
@@ -2163,13 +2139,11 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 {
        const char *pgm = external_diff();
        struct strbuf msg;
 {
        const char *pgm = external_diff();
        struct strbuf msg;
-       char *xfrm_msg;
        struct diff_filespec *one = p->one;
        struct diff_filespec *two = p->two;
        const char *name;
        const char *other;
        const char *attr_path;
        struct diff_filespec *one = p->one;
        struct diff_filespec *two = p->two;
        const char *name;
        const char *other;
        const char *attr_path;
-       int complete_rewrite = 0;
 
        name  = p->one->path;
        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 
        name  = p->one->path;
        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
@@ -2179,83 +2153,34 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 
        if (DIFF_PAIR_UNMERGED(p)) {
                run_diff_cmd(pgm, name, NULL, attr_path,
 
        if (DIFF_PAIR_UNMERGED(p)) {
                run_diff_cmd(pgm, name, NULL, attr_path,
-                            NULL, NULL, NULL, o, 0);
+                            NULL, NULL, NULL, o, p);
                return;
        }
 
        diff_fill_sha1_info(one);
        diff_fill_sha1_info(two);
 
                return;
        }
 
        diff_fill_sha1_info(one);
        diff_fill_sha1_info(two);
 
-       strbuf_init(&msg, PATH_MAX * 2 + 300);
-       switch (p->status) {
-       case DIFF_STATUS_COPIED:
-               strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
-               strbuf_addstr(&msg, "\ncopy from ");
-               quote_c_style(name, &msg, NULL, 0);
-               strbuf_addstr(&msg, "\ncopy to ");
-               quote_c_style(other, &msg, NULL, 0);
-               strbuf_addch(&msg, '\n');
-               break;
-       case DIFF_STATUS_RENAMED:
-               strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
-               strbuf_addstr(&msg, "\nrename from ");
-               quote_c_style(name, &msg, NULL, 0);
-               strbuf_addstr(&msg, "\nrename to ");
-               quote_c_style(other, &msg, NULL, 0);
-               strbuf_addch(&msg, '\n');
-               break;
-       case DIFF_STATUS_MODIFIED:
-               if (p->score) {
-                       strbuf_addf(&msg, "dissimilarity index %d%%\n",
-                                       similarity_index(p));
-                       complete_rewrite = 1;
-                       break;
-               }
-               /* fallthru */
-       default:
-               /* nothing */
-               ;
-       }
-
-       if (hashcmp(one->sha1, two->sha1)) {
-               int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
-
-               if (DIFF_OPT_TST(o, BINARY)) {
-                       mmfile_t mf;
-                       if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
-                           (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
-                               abbrev = 40;
-               }
-               strbuf_addf(&msg, "index %.*s..%.*s",
-                               abbrev, sha1_to_hex(one->sha1),
-                               abbrev, sha1_to_hex(two->sha1));
-               if (one->mode == two->mode)
-                       strbuf_addf(&msg, " %06o", one->mode);
-               strbuf_addch(&msg, '\n');
-       }
-
-       if (msg.len)
-               strbuf_setlen(&msg, msg.len - 1);
-       xfrm_msg = msg.len ? msg.buf : NULL;
-
        if (!pgm &&
            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
        if (!pgm &&
            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
-               /* a filepair that changes between file and symlink
+               /*
+                * a filepair that changes between file and symlink
                 * needs to be split into deletion and creation.
                 */
                struct diff_filespec *null = alloc_filespec(two->path);
                run_diff_cmd(NULL, name, other, attr_path,
                 * needs to be split into deletion and creation.
                 */
                struct diff_filespec *null = alloc_filespec(two->path);
                run_diff_cmd(NULL, name, other, attr_path,
-                            one, null, xfrm_msg, o, 0);
+                            one, null, &msg, o, p);
                free(null);
                free(null);
+               strbuf_release(&msg);
+
                null = alloc_filespec(one->path);
                run_diff_cmd(NULL, name, other, attr_path,
                null = alloc_filespec(one->path);
                run_diff_cmd(NULL, name, other, attr_path,
-                            null, two, xfrm_msg, o, 0);
+                            null, two, &msg, o, p);
                free(null);
        }
        else
                run_diff_cmd(pgm, name, other, attr_path,
                free(null);
        }
        else
                run_diff_cmd(pgm, name, other, attr_path,
-                            one, two, xfrm_msg, o, complete_rewrite);
+                            one, two, &msg, o, p);
 
        strbuf_release(&msg);
 }
 
        strbuf_release(&msg);
 }
@@ -2332,8 +2257,10 @@ void diff_setup(struct diff_options *options)
                DIFF_OPT_CLR(options, COLOR_DIFF);
        options->detect_rename = diff_detect_rename_default;
 
                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)
 }
 
 int diff_setup_done(struct diff_options *options)
@@ -2490,6 +2417,10 @@ 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 (!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;
        }
        else if (!strcmp(arg, "--check"))
                options->output_format |= DIFF_FORMAT_CHECKDIFF;
@@ -2594,6 +2525,10 @@ 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);
                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);
 
        else if (!strcmp(arg, "--ignore-submodules"))
                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
 
@@ -3046,8 +2981,7 @@ static void diff_summary(FILE *file, struct diff_filepair *p)
 }
 
 struct patch_id_t {
 }
 
 struct patch_id_t {
-       struct xdiff_emit_state xm;
-       SHA_CTX *ctx;
+       git_SHA_CTX *ctx;
        int patchlen;
 };
 
        int patchlen;
 };
 
@@ -3075,7 +3009,7 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
 
        new_len = remove_space(line, 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;
 }
 
        data->patchlen += new_len;
 }
 
@@ -3084,14 +3018,13 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
 {
        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];
 
        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;
        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;
 
        for (i = 0; i < q->nr; i++) {
                xpparam_t xpp;
@@ -3101,6 +3034,7 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                struct diff_filepair *p = q->queue[i];
                int len1, len2;
 
                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");
                memset(&xecfg, 0, sizeof(xecfg));
                if (p->status == 0)
                        return error("internal diff status error");
@@ -3151,17 +3085,16 @@ 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);
                                        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;
 
                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;
 }
 
        return 0;
 }
 
@@ -3235,7 +3168,6 @@ void diff_flush(struct diff_options *options)
                struct diffstat_t diffstat;
 
                memset(&diffstat, 0, sizeof(struct diffstat_t));
                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))
                for (i = 0; i < q->nr; i++) {
                        struct diff_filepair *p = q->queue[i];
                        if (check_pair_status(p))
@@ -3532,3 +3464,34 @@ void diff_unmerge(struct diff_options *options,
        fill_filespec(one, sha1, mode);
        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
 }
        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;
+
+       prepare_temp_file(spec->path, &temp, 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) {
+               if (temp.name == temp.tmp_path)
+                       unlink(temp.name);
+               error("error running textconv command '%s'", pgm);
+               return NULL;
+       }
+       if (temp.name == temp.tmp_path)
+               unlink(temp.name);
+
+       return strbuf_detach(&buf, outsize);
+}