revision traversal: prepare for commit log match.

This is from a suggestion by Linus, just to mark the locations where we
need to modify to actually implement the filtering.

We do not have any actual filtering code yet.

Signed-off-by: Junio C Hamano <junkio@cox.net>

revision.c

@@ -6,6 +6,8 @@
 #include "diff.h"
 #include "refs.h"
 #include "revision.h"
+#include <regex.h>
+#include "grep.h"
 
 static char *path_name(struct name_path *path, const char *name)
 {
@@ -1045,6 +1047,15 @@ static void mark_boundary_to_show(struct commit *commit)
 	}
 }
 
+static int commit_match(struct commit *commit, struct rev_info *opt)
+{
+	if (!opt->header_filter && !opt->message_filter)
+		return 1;
+
+	/* match it here */
+	return 1;
+}
+
 struct commit *get_revision(struct rev_info *revs)
 {
 	struct commit_list *list = revs->commits;
@@ -1105,6 +1116,8 @@ struct commit *get_revision(struct rev_info *revs)
 		if (revs->no_merges &&
 		    commit->parents && commit->parents->next)
 			continue;
+		if (!commit_match(commit, revs))
+			continue;
 		if (revs->prune_fn && revs->dense) {
 			/* Commit without changes? */
 			if (!(commit->object.flags & TREECHANGE)) {

revision.h

@@ -71,6 +71,10 @@ struct rev_info {
 	const char	*add_signoff;
 	const char	*extra_headers;
 
+	/* Filter by commit log message */
+	struct grep_opt	*header_filter;
+	struct grep_opt	*message_filter;
+
 	/* special limits */
 	int max_count;
 	unsigned long max_age;