[PATCH v2 3/3] diff: remove parseopts member from struct diff_options

[René Scharfe <l.s.r@xxxxxx>]

repo_diff_setup() builds the struct option array with git diff's command
line options and stores a pointer to it in the parseopts member of
struct diff_options.  The array is freed by diff_setup_done(), but not
by release_revisions().  Thus calling only repo_diff_setup() and
release_revisions() leaks that array.

We could free it in release_revisions() as well to plug that leak, but
there is a better way: Only build it when needed.  Move the
get_diff_parseopts() calls to the two places that use the array, free it
after use and get rid of the parseopts member.

Signed-off-by: René Scharfe <l.s.r@xxxxxx>
---
 diff.c | 17 ++++++++---------
 diff.h |  1 -
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/diff.c b/diff.c
index e469d5d2a0..6415c4dc2d 100644
--- a/diff.c
+++ b/diff.c
@@ -4615,8 +4615,6 @@ static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
 	builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
 }

-static struct option *get_diff_parseopts(struct diff_options *options);
-
 void repo_diff_setup(struct repository *r, struct diff_options *options)
 {
 	memcpy(options, &default_diff_options, sizeof(*options));
@@ -4662,8 +4660,6 @@ void repo_diff_setup(struct repository *r, struct diff_options *options)

 	options->color_moved = diff_color_moved_default;
 	options->color_moved_ws_handling = diff_color_moved_ws_default;
-
-	options->parseopts = get_diff_parseopts(options);
 }

 static const char diff_status_letters[] = {
@@ -4821,8 +4817,6 @@ void diff_setup_done(struct diff_options *options)
 			options->filter = ~filter_bit[DIFF_STATUS_FILTER_AON];
 		options->filter &= ~options->filter_not;
 	}
-
-	FREE_AND_NULL(options->parseopts);
 }

 int parse_long_opt(const char *opt, const char **argv,
@@ -5695,21 +5689,27 @@ static struct option *get_diff_parseopts(struct diff_options *options)
 struct option *add_diff_options(const struct option *parseopts,
 				struct diff_options *options)
 {
-	return parse_options_concat(parseopts, options->parseopts);
+	struct option *diff_parseopts = get_diff_parseopts(options);
+	struct option *result = parse_options_concat(parseopts, diff_parseopts);
+	free(diff_parseopts);
+	return result;
 }

 int diff_opt_parse(struct diff_options *options,
 		   const char **av, int ac, const char *prefix)
 {
+	struct option *diff_parseopts = get_diff_parseopts(options);
+
 	if (!prefix)
 		prefix = "";

-	ac = parse_options(ac, av, prefix, options->parseopts, NULL,
+	ac = parse_options(ac, av, prefix, diff_parseopts, NULL,
 			   PARSE_OPT_KEEP_DASHDASH |
 			   PARSE_OPT_KEEP_UNKNOWN_OPT |
 			   PARSE_OPT_NO_INTERNAL_HELP |
 			   PARSE_OPT_ONE_SHOT |
 			   PARSE_OPT_STOP_AT_NON_OPTION);
+	free(diff_parseopts);

 	return ac;
 }
@@ -6518,7 +6518,6 @@ void diff_free(struct diff_options *options)
 	diff_free_file(options);
 	diff_free_ignore_regex(options);
 	clear_pathspec(&options->pathspec);
-	FREE_AND_NULL(options->parseopts);
 }

 void diff_flush(struct diff_options *options)
diff --git a/diff.h b/diff.h
index c20a1ad76d..41eb2c3d42 100644
--- a/diff.h
+++ b/diff.h
@@ -394,7 +394,6 @@ struct diff_options {
 	unsigned color_moved_ws_handling;

 	struct repository *repo;
-	struct option *parseopts;
 	struct strmap *additional_path_headers;

 	int no_free;
--
2.38.1