grep: drop grep_buffer's "name" parameter

Before the grep_source interface existed, grep_buffer was
used by two types of callers:

  1. Ones which pulled a file into a buffer, and then wanted
     to supply the file's name for the output (i.e.,
     git grep).

  2. Ones which really just wanted to grep a buffer (i.e.,
     git log --grep).

Callers in set (1) should now be using grep_source. Callers
in set (2) always pass NULL for the "name" parameter of
grep_buffer. We can therefore get rid of this now-useless
parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

grep.c

@@ -1215,12 +1215,12 @@ int grep_source(struct grep_opt *opt, struct grep_source *gs)
 	return grep_source_1(opt, gs, 0);
 }
 
-int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size)
+int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
 {
 	struct grep_source gs;
 	int r;
 
-	grep_source_init(&gs, GREP_SOURCE_BUF, name, NULL);
+	grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL);
 	gs.buf = buf;
 	gs.size = size;
 

grep.h

@@ -127,7 +127,7 @@ extern void append_grep_pattern(struct grep_opt *opt, const char *pat, const cha
 extern void append_header_grep_pattern(struct grep_opt *, enum grep_header_field, const char *);
 extern void compile_grep_patterns(struct grep_opt *opt);
 extern void free_grep_patterns(struct grep_opt *opt);
-extern int grep_buffer(struct grep_opt *opt, const char *name, char *buf, unsigned long size);
+extern int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size);
 
 struct grep_source {
 	char *name;

revision.c

@@ -2128,7 +2128,6 @@ static int commit_match(struct commit *commit, struct rev_info *opt)
 	if (!opt->grep_filter.pattern_list && !opt->grep_filter.header_list)
 		return 1;
 	return grep_buffer(&opt->grep_filter,
-			   NULL, /* we say nothing, not even filename */
 			   commit->buffer, strlen(commit->buffer));
 }