ref-filter.c: parameterize match functions over patterns

`match_pattern()` and `match_name_as_path()` both take a `struct
ref_filter *`, and then store a stack variable `patterns` pointing at
`filter->patterns`.

The subsequent patch will add a new array of patterns to match over (the
excluded patterns, via a new `git for-each-ref --exclude` option),
treating the return value of these functions differently depending on
which patterns are being used to match.

Tweak `match_pattern()` and `match_name_as_path()` to take an array of
patterns to prepare for passing either in.

Once we start passing either in, `match_pattern()` will have little to
do with a particular `struct ref_filter *` instance. To clarify this,
drop it from the argument list, and replace it with the only bit of the
`ref_filter` that we care about (`filter->ignore_case`).

Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ref-filter.c

@@ -2104,12 +2104,12 @@ static int get_ref_atom_value(struct ref_array_item *ref, int atom,
  * matches a pattern "refs/heads/mas") or a wildcard (e.g. the same ref
  * matches "refs/heads/mas*", too).
  */
-static int match_pattern(const struct ref_filter *filter, const char *refname)
+static int match_pattern(const char **patterns, const char *refname,
+			 int ignore_case)
 {
-	const char **patterns = filter->name_patterns;
 	unsigned flags = 0;
 
-	if (filter->ignore_case)
+	if (ignore_case)
 		flags |= WM_CASEFOLD;
 
 	/*
@@ -2134,13 +2134,13 @@ static int match_pattern(const struct ref_filter *filter, const char *refname)
  * matches a pattern "refs/heads/" but not "refs/heads/m") or a
  * wildcard (e.g. the same ref matches "refs/heads/m*", too).
  */
-static int match_name_as_path(const struct ref_filter *filter, const char *refname)
+static int match_name_as_path(const char **pattern, const char *refname,
+			      int ignore_case)
 {
-	const char **pattern = filter->name_patterns;
 	int namelen = strlen(refname);
 	unsigned flags = WM_PATHNAME;
 
-	if (filter->ignore_case)
+	if (ignore_case)
 		flags |= WM_CASEFOLD;
 
 	for (; *pattern; pattern++) {
@@ -2165,8 +2165,10 @@ static int filter_pattern_match(struct ref_filter *filter, const char *refname)
 	if (!*filter->name_patterns)
 		return 1; /* No pattern always matches */
 	if (filter->match_as_path)
-		return match_name_as_path(filter, refname);
-	return match_pattern(filter, refname);
+		return match_name_as_path(filter->name_patterns, refname,
+					  filter->ignore_case);
+	return match_pattern(filter->name_patterns, refname,
+			     filter->ignore_case);
 }
 
 /*