Merge branch 'jc/grep-lookahead'
authorJunio C Hamano <gitster@pobox.com>
Wed, 20 Jan 2010 22:43:41 +0000 (14:43 -0800)
committerJunio C Hamano <gitster@pobox.com>
Wed, 20 Jan 2010 22:43:41 +0000 (14:43 -0800)
* jc/grep-lookahead:
  grep --no-index: allow use of "git grep" outside a git repository
  grep: prepare to run outside of a work tree
  grep: rip out pessimization to use fixmatch()
  grep: rip out support for external grep
  grep: optimize built-in grep by skipping lines that do not hit

Conflicts:
builtin-grep.c
t/t7002-grep.sh

Documentation/config.txt
Makefile
builtin-grep.c
git.c
grep.c
grep.h
t/t7002-grep.sh

index 76c7d9c..d40b83f 100644 (file)
@@ -664,14 +664,6 @@ color.grep::
        `never`), never.  When set to `true` or `auto`, use color only
        when the output is written to the terminal.  Defaults to `false`.
 
-color.grep.external::
-       The string value of this variable is passed to an external 'grep'
-       command as a command line option if match highlighting is turned
-       on.  If set to an empty string, no option is passed at all,
-       turning off coloring for external 'grep' calls; this is the default.
-       For GNU grep, set it to `--color=always` to highlight matches even
-       when a pager is used.
-
 color.grep.match::
        Use customized color for matches.  The value of this variable
        may be specified as in color.branch.<slot>.  It is passed using
index b7f56b7..d74c196 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -187,10 +187,6 @@ all::
 # is a simplified version of the merge sort used in glibc. This is
 # recommended if Git triggers O(n^2) behavior in your platform's qsort().
 #
-# Define NO_EXTERNAL_GREP if you don't want "git grep" to ever call
-# your external grep (e.g., if your system lacks grep, if its grep is
-# broken, or spawning external process is slower than built-in grep git has).
-#
 # Define UNRELIABLE_FSTAT if your system's fstat does not return the same
 # information on a not yet closed file that lstat would return for the same
 # file after it was closed.
@@ -795,7 +791,6 @@ ifeq ($(uname_S),SunOS)
        NO_MKDTEMP = YesPlease
        NO_MKSTEMPS = YesPlease
        NO_REGEX = YesPlease
-       NO_EXTERNAL_GREP = YesPlease
        THREADED_DELTA_SEARCH = YesPlease
        ifeq ($(uname_R),5.7)
                NEEDS_RESOLV = YesPlease
@@ -914,7 +909,6 @@ ifeq ($(uname_S),IRIX)
        # NO_MMAP.  If you suspect that your compiler is not affected by this
        # issue, comment out the NO_MMAP statement.
        NO_MMAP = YesPlease
-       NO_EXTERNAL_GREP = UnfortunatelyYes
        SNPRINTF_RETURNS_BOGUS = YesPlease
        SHELL_PATH = /usr/gnu/bin/bash
        NEEDS_LIBGEN = YesPlease
@@ -934,7 +928,6 @@ ifeq ($(uname_S),IRIX64)
        # NO_MMAP.  If you suspect that your compiler is not affected by this
        # issue, comment out the NO_MMAP statement.
        NO_MMAP = YesPlease
-       NO_EXTERNAL_GREP = UnfortunatelyYes
        SNPRINTF_RETURNS_BOGUS = YesPlease
        SHELL_PATH=/usr/gnu/bin/bash
        NEEDS_LIBGEN = YesPlease
@@ -1349,9 +1342,6 @@ endif
 ifdef DIR_HAS_BSD_GROUP_SEMANTICS
        COMPAT_CFLAGS += -DDIR_HAS_BSD_GROUP_SEMANTICS
 endif
-ifdef NO_EXTERNAL_GREP
-       BASIC_CFLAGS += -DNO_EXTERNAL_GREP
-endif
 ifdef UNRELIABLE_FSTAT
        BASIC_CFLAGS += -DUNRELIABLE_FSTAT
 endif
index cea973b..da854fa 100644 (file)
 #include "userdiff.h"
 #include "grep.h"
 #include "quote.h"
-
-#ifndef NO_EXTERNAL_GREP
-#ifdef __unix__
-#define NO_EXTERNAL_GREP 0
-#else
-#define NO_EXTERNAL_GREP 1
-#endif
-#endif
+#include "dir.h"
 
 static char const * const grep_usage[] = {
        "git grep [options] [-e] <pattern> [<rev>...] [[--] path...]",
@@ -42,8 +35,6 @@ static int grep_config(const char *var, const char *value, void *cb)
                opt->color = git_config_colorbool(var, value, -1);
                return 0;
        }
-       if (!strcmp(var, "color.grep.external"))
-               return git_config_string(&(opt->color_external), var, value);
        if (!strcmp(var, "color.grep.match")) {
                if (!value)
                        return config_error_nonbool(var);
@@ -214,309 +205,12 @@ static int grep_file(struct grep_opt *opt, const char *filename)
        return i;
 }
 
-#if !NO_EXTERNAL_GREP
-static int exec_grep(int argc, const char **argv)
-{
-       pid_t pid;
-       int status;
-
-       argv[argc] = NULL;
-       trace_argv_printf(argv, "trace: grep:");
-       pid = fork();
-       if (pid < 0)
-               return pid;
-       if (!pid) {
-               execvp("grep", (char **) argv);
-               exit(255);
-       }
-       while (waitpid(pid, &status, 0) < 0) {
-               if (errno == EINTR)
-                       continue;
-               return -1;
-       }
-       if (WIFEXITED(status)) {
-               if (!WEXITSTATUS(status))
-                       return 1;
-               return 0;
-       }
-       return -1;
-}
-
-#define MAXARGS 1000
-#define ARGBUF 4096
-#define push_arg(a) do { \
-       if (nr < MAXARGS) argv[nr++] = (a); \
-       else die("maximum number of args exceeded"); \
-       } while (0)
-
-/*
- * If you send a singleton filename to grep, it does not give
- * the name of the file.  GNU grep has "-H" but we would want
- * that behaviour in a portable way.
- *
- * So we keep two pathnames in argv buffer unsent to grep in
- * the main loop if we need to do more than one grep.
- */
-static int flush_grep(struct grep_opt *opt,
-                     int argc, int arg0, const char **argv, int *kept)
-{
-       int status;
-       int count = argc - arg0;
-       const char *kept_0 = NULL;
-
-       if (count <= 2) {
-               /*
-                * Because we keep at least 2 paths in the call from
-                * the main loop (i.e. kept != NULL), and MAXARGS is
-                * far greater than 2, this usually is a call to
-                * conclude the grep.  However, the user could attempt
-                * to overflow the argv buffer by giving too many
-                * options to leave very small number of real
-                * arguments even for the call in the main loop.
-                */
-               if (kept)
-                       die("insanely many options to grep");
-
-               /*
-                * If we have two or more paths, we do not have to do
-                * anything special, but we need to push /dev/null to
-                * get "-H" behaviour of GNU grep portably but when we
-                * are not doing "-l" nor "-L" nor "-c".
-                */
-               if (count == 1 &&
-                   !opt->name_only &&
-                   !opt->unmatch_name_only &&
-                   !opt->count) {
-                       argv[argc++] = "/dev/null";
-                       argv[argc] = NULL;
-               }
-       }
-
-       else if (kept) {
-               /*
-                * Called because we found many paths and haven't finished
-                * iterating over the cache yet.  We keep two paths
-                * for the concluding call.  argv[argc-2] and argv[argc-1]
-                * has the last two paths, so save the first one away,
-                * replace it with NULL while sending the list to grep,
-                * and recover them after we are done.
-                */
-               *kept = 2;
-               kept_0 = argv[argc-2];
-               argv[argc-2] = NULL;
-               argc -= 2;
-       }
-
-       if (opt->pre_context || opt->post_context) {
-               /*
-                * grep handles hunk marks between files, but we need to
-                * do that ourselves between multiple calls.
-                */
-               if (opt->show_hunk_mark)
-                       write_or_die(1, "--\n", 3);
-               else
-                       opt->show_hunk_mark = 1;
-       }
-
-       status = exec_grep(argc, argv);
-
-       if (kept_0) {
-               /*
-                * Then recover them.  Now the last arg is beyond the
-                * terminating NULL which is at argc, and the second
-                * from the last is what we saved away in kept_0
-                */
-               argv[arg0++] = kept_0;
-               argv[arg0] = argv[argc+1];
-       }
-       return status;
-}
-
-static void grep_add_color(struct strbuf *sb, const char *escape_seq)
-{
-       size_t orig_len = sb->len;
-
-       while (*escape_seq) {
-               if (*escape_seq == 'm')
-                       strbuf_addch(sb, ';');
-               else if (*escape_seq != '\033' && *escape_seq  != '[')
-                       strbuf_addch(sb, *escape_seq);
-               escape_seq++;
-       }
-       if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
-               strbuf_setlen(sb, sb->len - 1);
-}
-
-static int has_skip_worktree_entry(struct grep_opt *opt, const char **paths)
-{
-       int nr;
-       for (nr = 0; nr < active_nr; nr++) {
-               struct cache_entry *ce = active_cache[nr];
-               if (!S_ISREG(ce->ce_mode))
-                       continue;
-               if (!pathspec_matches(paths, ce->name, opt->max_depth))
-                       continue;
-               if (ce_skip_worktree(ce))
-                       return 1;
-       }
-       return 0;
-}
-
-static int external_grep(struct grep_opt *opt, const char **paths, int cached)
-{
-       int i, nr, argc, hit, len, status;
-       const char *argv[MAXARGS+1];
-       char randarg[ARGBUF];
-       char *argptr = randarg;
-       struct grep_pat *p;
-
-       if (opt->extended || (opt->relative && opt->prefix_length)
-           || has_skip_worktree_entry(opt, paths))
-               return -1;
-       len = nr = 0;
-       push_arg("grep");
-       if (opt->fixed)
-               push_arg("-F");
-       if (opt->linenum)
-               push_arg("-n");
-       if (!opt->pathname)
-               push_arg("-h");
-       if (opt->regflags & REG_EXTENDED)
-               push_arg("-E");
-       if (opt->ignore_case)
-               push_arg("-i");
-       if (opt->binary == GREP_BINARY_NOMATCH)
-               push_arg("-I");
-       if (opt->word_regexp)
-               push_arg("-w");
-       if (opt->name_only)
-               push_arg("-l");
-       if (opt->unmatch_name_only)
-               push_arg("-L");
-       if (opt->null_following_name)
-               /* in GNU grep git's "-z" translates to "-Z" */
-               push_arg("-Z");
-       if (opt->count)
-               push_arg("-c");
-       if (opt->post_context || opt->pre_context) {
-               if (opt->post_context != opt->pre_context) {
-                       if (opt->pre_context) {
-                               push_arg("-B");
-                               len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->pre_context) + 1;
-                               if (sizeof(randarg) <= len)
-                                       die("maximum length of args exceeded");
-                               push_arg(argptr);
-                               argptr += len;
-                       }
-                       if (opt->post_context) {
-                               push_arg("-A");
-                               len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->post_context) + 1;
-                               if (sizeof(randarg) <= len)
-                                       die("maximum length of args exceeded");
-                               push_arg(argptr);
-                               argptr += len;
-                       }
-               }
-               else {
-                       push_arg("-C");
-                       len += snprintf(argptr, sizeof(randarg)-len,
-                                       "%u", opt->post_context) + 1;
-                       if (sizeof(randarg) <= len)
-                               die("maximum length of args exceeded");
-                       push_arg(argptr);
-                       argptr += len;
-               }
-       }
-       for (p = opt->pattern_list; p; p = p->next) {
-               push_arg("-e");
-               push_arg(p->pattern);
-       }
-       if (opt->color) {
-               struct strbuf sb = STRBUF_INIT;
-
-               grep_add_color(&sb, opt->color_match);
-               setenv("GREP_COLOR", sb.buf, 1);
-
-               strbuf_reset(&sb);
-               strbuf_addstr(&sb, "mt=");
-               grep_add_color(&sb, opt->color_match);
-               strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
-               setenv("GREP_COLORS", sb.buf, 1);
-
-               strbuf_release(&sb);
-
-               if (opt->color_external && strlen(opt->color_external) > 0)
-                       push_arg(opt->color_external);
-       } else {
-               unsetenv("GREP_COLOR");
-               unsetenv("GREP_COLORS");
-       }
-       unsetenv("GREP_OPTIONS");
-
-       hit = 0;
-       argc = nr;
-       for (i = 0; i < active_nr; i++) {
-               struct cache_entry *ce = active_cache[i];
-               char *name;
-               int kept;
-               if (!S_ISREG(ce->ce_mode))
-                       continue;
-               if (!pathspec_matches(paths, ce->name, opt->max_depth))
-                       continue;
-               name = ce->name;
-               if (name[0] == '-') {
-                       int len = ce_namelen(ce);
-                       name = xmalloc(len + 3);
-                       memcpy(name, "./", 2);
-                       memcpy(name + 2, ce->name, len + 1);
-               }
-               argv[argc++] = name;
-               if (MAXARGS <= argc) {
-                       status = flush_grep(opt, argc, nr, argv, &kept);
-                       if (0 < status)
-                               hit = 1;
-                       argc = nr + kept;
-               }
-               if (ce_stage(ce)) {
-                       do {
-                               i++;
-                       } while (i < active_nr &&
-                                !strcmp(ce->name, active_cache[i]->name));
-                       i--; /* compensate for loop control */
-               }
-       }
-       if (argc > nr) {
-               status = flush_grep(opt, argc, nr, argv, NULL);
-               if (0 < status)
-                       hit = 1;
-       }
-       return hit;
-}
-#endif
-
-static int grep_cache(struct grep_opt *opt, const char **paths, int cached,
-                     int external_grep_allowed)
+static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 {
        int hit = 0;
        int nr;
        read_cache();
 
-#if !NO_EXTERNAL_GREP
-       /*
-        * Use the external "grep" command for the case where
-        * we grep through the checked-out files. It tends to
-        * be a lot more optimized
-        */
-       if (!cached && external_grep_allowed) {
-               hit = external_grep(opt, paths, cached);
-               if (hit >= 0)
-                       return hit;
-               hit = 0;
-       }
-#endif
-
        for (nr = 0; nr < active_nr; nr++) {
                struct cache_entry *ce = active_cache[nr];
                if (!S_ISREG(ce->ce_mode))
@@ -626,6 +320,21 @@ static int grep_object(struct grep_opt *opt, const char **paths,
        die("unable to grep from object of type %s", typename(obj->type));
 }
 
+static int grep_directory(struct grep_opt *opt, const char **paths)
+{
+       struct dir_struct dir;
+       int i, hit = 0;
+
+       memset(&dir, 0, sizeof(dir));
+       setup_standard_excludes(&dir);
+
+       fill_directory(&dir, paths);
+       for (i = 0; i < dir.nr; i++)
+               hit |= grep_file(opt, dir.entries[i]->name);
+       free_grep_patterns(opt);
+       return hit;
+}
+
 static int context_callback(const struct option *opt, const char *arg,
                            int unset)
 {
@@ -713,16 +422,19 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 {
        int hit = 0;
        int cached = 0;
-       int external_grep_allowed = 1;
        int seen_dashdash = 0;
+       int external_grep_allowed__ignored;
        struct grep_opt opt;
        struct object_array list = { 0, 0, NULL };
        const char **paths = NULL;
        int i;
        int dummy;
+       int nongit = 0, use_index = 1;
        struct option options[] = {
                OPT_BOOLEAN(0, "cached", &cached,
                        "search in index instead of in the work tree"),
+               OPT_BOOLEAN(0, "index", &use_index,
+                       "--no-index finds in contents not managed by git"),
                OPT_GROUP(""),
                OPT_BOOLEAN('v', "invert-match", &opt.invert,
                        "show non-matching lines"),
@@ -796,18 +508,15 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                OPT_BOOLEAN(0, "all-match", &opt.all_match,
                        "show only matches from files that match all patterns"),
                OPT_GROUP(""),
-#if NO_EXTERNAL_GREP
-               OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
-                       "allow calling of grep(1) (ignored by this build)"),
-#else
-               OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
-                       "allow calling of grep(1) (default)"),
-#endif
+               OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed__ignored,
+                           "allow calling of grep(1) (ignored by this build)"),
                { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
                  PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
                OPT_END()
        };
 
+       prefix = setup_git_directory_gently(&nongit);
+
        /*
         * 'git grep -h', unlike 'git grep -h <pattern>', is a request
         * to show usage information and exit.
@@ -845,6 +554,10 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                             PARSE_OPT_STOP_AT_NON_OPTION |
                             PARSE_OPT_NO_INTERNAL_HELP);
 
+       if (use_index && nongit)
+               /* die the same way as if we did it at the beginning */
+               setup_git_directory();
+
        /* First unrecognized non-option token */
        if (argc > 0 && !opt.pattern_list) {
                append_grep_pattern(&opt, argv[0], "command line", 0,
@@ -853,8 +566,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                argc--;
        }
 
-       if ((opt.color && !opt.color_external) || opt.funcname)
-               external_grep_allowed = 0;
        if (!opt.pattern_list)
                die("no pattern given.");
        if (!opt.fixed && opt.ignore_case)
@@ -897,10 +608,18 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                paths[1] = NULL;
        }
 
+       if (!use_index) {
+               if (cached)
+                       die("--cached cannot be used with --no-index.");
+               if (list.nr)
+                       die("--no-index cannot be used with revs.");
+               return !grep_directory(&opt, paths);
+       }
+
        if (!list.nr) {
                if (!cached)
                        setup_work_tree();
-               return !grep_cache(&opt, paths, cached, external_grep_allowed);
+               return !grep_cache(&opt, paths, cached);
        }
 
        if (cached)
diff --git a/git.c b/git.c
index 11544cd..ad07473 100644 (file)
--- a/git.c
+++ b/git.c
@@ -317,7 +317,7 @@ static void handle_internal_command(int argc, const char **argv)
                { "fsck-objects", cmd_fsck, RUN_SETUP },
                { "gc", cmd_gc, RUN_SETUP },
                { "get-tar-commit-id", cmd_get_tar_commit_id },
-               { "grep", cmd_grep, RUN_SETUP | USE_PAGER },
+               { "grep", cmd_grep, USE_PAGER },
                { "help", cmd_help },
                { "init", cmd_init_db },
                { "init-db", cmd_init_db },
diff --git a/grep.c b/grep.c
index bdadf2c..8e1f7de 100644 (file)
--- a/grep.c
+++ b/grep.c
@@ -29,13 +29,6 @@ void append_grep_pattern(struct grep_opt *opt, const char *pat,
        p->next = NULL;
 }
 
-static int is_fixed(const char *s)
-{
-       while (*s && !is_regex_special(*s))
-               s++;
-       return !*s;
-}
-
 static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
 {
        int err;
@@ -43,7 +36,7 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
        p->word_regexp = opt->word_regexp;
        p->ignore_case = opt->ignore_case;
 
-       if (opt->fixed || is_fixed(p->pattern))
+       if (opt->fixed)
                p->fixed = 1;
        if (opt->regflags & REG_ICASE)
                p->fixed = 0;
@@ -615,6 +608,65 @@ static void show_pre_context(struct grep_opt *opt, const char *name, char *buf,
        }
 }
 
+static int should_lookahead(struct grep_opt *opt)
+{
+       struct grep_pat *p;
+
+       if (opt->extended)
+               return 0; /* punt for too complex stuff */
+       if (opt->invert)
+               return 0;
+       for (p = opt->pattern_list; p; p = p->next) {
+               if (p->token != GREP_PATTERN)
+                       return 0; /* punt for "header only" and stuff */
+       }
+       return 1;
+}
+
+static int look_ahead(struct grep_opt *opt,
+                     unsigned long *left_p,
+                     unsigned *lno_p,
+                     char **bol_p)
+{
+       unsigned lno = *lno_p;
+       char *bol = *bol_p;
+       struct grep_pat *p;
+       char *sp, *last_bol;
+       regoff_t earliest = -1;
+
+       for (p = opt->pattern_list; p; p = p->next) {
+               int hit;
+               regmatch_t m;
+
+               if (p->fixed)
+                       hit = !fixmatch(p->pattern, bol, p->ignore_case, &m);
+               else
+                       hit = !regexec(&p->regexp, bol, 1, &m, 0);
+               if (!hit || m.rm_so < 0 || m.rm_eo < 0)
+                       continue;
+               if (earliest < 0 || m.rm_so < earliest)
+                       earliest = m.rm_so;
+       }
+
+       if (earliest < 0) {
+               *bol_p = bol + *left_p;
+               *left_p = 0;
+               return 1;
+       }
+       for (sp = bol + earliest; bol < sp && sp[-1] != '\n'; sp--)
+               ; /* find the beginning of the line */
+       last_bol = sp;
+
+       for (sp = bol; sp < last_bol; sp++) {
+               if (*sp == '\n')
+                       lno++;
+       }
+       *left_p -= last_bol - bol;
+       *bol_p = last_bol;
+       *lno_p = lno;
+       return 0;
+}
+
 static int grep_buffer_1(struct grep_opt *opt, const char *name,
                         char *buf, unsigned long size, int collect_hits)
 {
@@ -624,6 +676,7 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
        unsigned last_hit = 0;
        int binary_match_only = 0;
        unsigned count = 0;
+       int try_lookahead = 0;
        enum grep_context ctx = GREP_CONTEXT_HEAD;
        xdemitconf_t xecfg;
 
@@ -652,11 +705,26 @@ static int grep_buffer_1(struct grep_opt *opt, const char *name,
                        opt->priv = &xecfg;
                }
        }
+       try_lookahead = should_lookahead(opt);
 
        while (left) {
                char *eol, ch;
                int hit;
 
+               /*
+                * look_ahead() skips quicly to the line that possibly
+                * has the next hit; don't call it if we need to do
+                * something more than just skipping the current line
+                * in response to an unmatch for the current line.  E.g.
+                * inside a post-context window, we will show the current
+                * line as a context around the previous hit when it
+                * doesn't hit.
+                */
+               if (try_lookahead
+                   && !(last_hit
+                        && lno <= last_hit + opt->post_context)
+                   && look_ahead(opt, &left, &lno, &bol))
+                       break;
                eol = end_of_line(bol, &left);
                ch = *eol;
                *eol = 0;
diff --git a/grep.h b/grep.h
index 75370f6..0c61b00 100644 (file)
--- a/grep.h
+++ b/grep.h
@@ -85,7 +85,6 @@ struct grep_opt {
        int max_depth;
        int funcname;
        char color_match[COLOR_MAXLEN];
-       const char *color_external;
        int regflags;
        unsigned pre_context;
        unsigned post_context;
index 76c5e09..7eceb08 100755 (executable)
@@ -8,18 +8,6 @@ test_description='git grep various.
 
 . ./test-lib.sh
 
-test_expect_success 'Check for external grep support' '
-       case "$(git grep -h 2>&1|grep ext-grep)" in
-       *"(default)"*)
-               test_set_prereq EXTGREP
-               true;;
-       *"(ignored by this build)"*)
-               true;;
-       *)
-               false;;
-       esac
-'
-
 cat >hello.c <<EOF
 #include <stdio.h>
 int main(int argc, const char **argv)
@@ -314,8 +302,8 @@ test_expect_success 'grep -C1, hunk mark between files' '
        test_cmp expected actual
 '
 
-test_expect_success 'grep -C1 --no-ext-grep, hunk mark between files' '
-       git grep -C1 --no-ext-grep "^[yz]" >actual &&
+test_expect_success 'grep -C1 hunk mark between files' '
+       git grep -C1 "^[yz]" >actual &&
        test_cmp expected actual
 '
 
@@ -371,7 +359,7 @@ test_expect_success 'log grep (6)' '
 test_expect_success 'grep with CE_VALID file' '
        git update-index --assume-unchanged t/t &&
        rm t/t &&
-       test "$(git grep --no-ext-grep test)" = "t/t:test" &&
+       test "$(git grep test)" = "t/t:test" &&
        git update-index --no-assume-unchanged t/t &&
        git checkout t/t
 '
@@ -438,16 +426,56 @@ test_expect_success 'grep -Fi' '
        test_cmp expected actual
 '
 
-test_expect_success EXTGREP 'external grep is called' '
-       GIT_TRACE=2 git grep foo >/dev/null 2>actual &&
-       grep "trace: grep:.*foo" actual >/dev/null
+test_expect_success 'outside of git repository' '
+       rm -fr non &&
+       mkdir -p non/git/sub &&
+       echo hello >non/git/file1 &&
+       echo world >non/git/sub/file2 &&
+       echo ".*o*" >non/git/.gitignore &&
+       {
+               echo file1:hello &&
+               echo sub/file2:world
+       } >non/expect.full &&
+       echo file2:world >non/expect.sub
+       (
+               GIT_CEILING_DIRECTORIES="$(pwd)/non/git" &&
+               export GIT_CEILING_DIRECTORIES &&
+               cd non/git &&
+               test_must_fail git grep o &&
+               git grep --no-index o >../actual.full &&
+               test_cmp ../expect.full ../actual.full
+               cd sub &&
+               test_must_fail git grep o &&
+               git grep --no-index o >../../actual.sub &&
+               test_cmp ../../expect.sub ../../actual.sub
+       )
 '
 
-test_expect_success EXTGREP 'no external grep when skip-worktree entries exist' '
-       git update-index --skip-worktree file &&
-       GIT_TRACE=2 git grep foo >/dev/null 2>actual &&
-       ! grep "trace: grep:" actual >/dev/null &&
-       git update-index --no-skip-worktree file
+test_expect_success 'inside git repository but with --no-index' '
+       rm -fr is &&
+       mkdir -p is/git/sub &&
+       echo hello >is/git/file1 &&
+       echo world >is/git/sub/file2 &&
+       echo ".*o*" >is/git/.gitignore &&
+       {
+               echo file1:hello &&
+               echo sub/file2:world
+       } >is/expect.full &&
+       : >is/expect.empty &&
+       echo file2:world >is/expect.sub
+       (
+               cd is/git &&
+               git init &&
+               test_must_fail git grep o >../actual.full &&
+               test_cmp ../expect.empty ../actual.full &&
+               git grep --no-index o >../actual.full &&
+               test_cmp ../expect.full ../actual.full &&
+               cd sub &&
+               test_must_fail git grep o >../../actual.sub &&
+               test_cmp ../../expect.empty ../../actual.sub &&
+               git grep --no-index o >../../actual.sub &&
+               test_cmp ../../expect.sub ../../actual.sub
+       )
 '
 
 test_done