pickaxe: pass diff_options to contains and has_changes

Remove the unused parameter needle from contains() and has_changes().

Also replace the parameter len with a pointer to the diff_options.  We
can use its member pickaxe to check if the needle is an empty string
and use the kwsmatch structure to find out the length of the match
instead.

This change is done as a preparation to unify the signatures of
has_changes() and diff_grep(), which will be used in the patch after
the next one to factor out common code.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diffcore-pickaxe.c

@@ -144,14 +144,13 @@ static void diffcore_pickaxe_grep(struct diff_options *o)
 	return;
 }
 
-static unsigned int contains(struct diff_filespec *one,
-			     const char *needle, unsigned long len,
+static unsigned int contains(struct diff_filespec *one, struct diff_options *o,
 			     regex_t *regexp, kwset_t kws)
 {
 	unsigned int cnt;
 	unsigned long sz;
 	const char *data;
-	if (!len)
+	if (!o->pickaxe[0])
 		return 0;
 	if (diff_populate_filespec(one, 0))
 		return 0;
@@ -175,35 +174,36 @@ static unsigned int contains(struct diff_filespec *one,
 
 	} else { /* Classic exact string match */
 		while (sz) {
-			size_t offset = kwsexec(kws, data, sz, NULL);
+			struct kwsmatch kwsm;
+			size_t offset = kwsexec(kws, data, sz, &kwsm);
 			const char *found;
 			if (offset == -1)
 				break;
 			else
 				found = data + offset;
-			sz -= found - data + len;
-			data = found + len;
+			sz -= found - data + kwsm.size[0];
+			data = found + kwsm.size[0];
 			cnt++;
 		}
 	}
 	diff_free_filespec_data(one);
 	return cnt;
 }
 
-static int has_changes(struct diff_filepair *p, const char *needle,
-		       unsigned long len, regex_t *regexp, kwset_t kws)
+static int has_changes(struct diff_filepair *p, struct diff_options *o,
+		       regex_t *regexp, kwset_t kws)
 {
 	if (!DIFF_FILE_VALID(p->one)) {
 		if (!DIFF_FILE_VALID(p->two))
 			return 0; /* ignore unmerged */
 		/* created */
-		return contains(p->two, needle, len, regexp, kws) != 0;
+		return contains(p->two, o, regexp, kws) != 0;
 	}
 	if (!DIFF_FILE_VALID(p->two))
-		return contains(p->one, needle, len, regexp, kws) != 0;
+		return contains(p->one, o, regexp, kws) != 0;
 	if (!diff_unmodified_pair(p)) {
-		return contains(p->one, needle, len, regexp, kws) !=
-		       contains(p->two, needle, len, regexp, kws);
+		return contains(p->one, o, regexp, kws) !=
+		       contains(p->two, o, regexp, kws);
 	}
 	return 0;
 }
@@ -241,7 +241,7 @@ static void diffcore_pickaxe_count(struct diff_options *o)
 		/* Showing the whole changeset if needle exists */
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
-			if (has_changes(p, needle, len, regexp, kws))
+			if (has_changes(p, o, regexp, kws))
 				goto out; /* do not munge the queue */
 		}
 
@@ -257,7 +257,7 @@ static void diffcore_pickaxe_count(struct diff_options *o)
 		/* Showing only the filepairs that has the needle */
 		for (i = 0; i < q->nr; i++) {
 			struct diff_filepair *p = q->queue[i];
-			if (has_changes(p, needle, len, regexp, kws))
+			if (has_changes(p, o, regexp, kws))
 				diff_q(&outq, p);
 			else
 				diff_free_filepair(p);