Free reflists after usage

Free reflists in cgit_print_branches() and in cgit_print_tags() before
returning reflist structures to the stack.

This fixes following memory leaks seen with "PATH_INFO=/cgit/refs/":

    ==5710== 1,312 (32 direct, 1,280 indirect) bytes in 1 blocks are definitely lost in loss record 63 of 71
    ==5710==    at 0x4C2C04B: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==5710==    by 0x4C2C2FF: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==5710==    by 0x46CA9B: xrealloc (wrapper.c:100)
    ==5710==    by 0x40AAA6: cgit_add_ref (shared.c:156)
    ==5710==    by 0x40ABC4: cgit_refs_cb (shared.c:186)
    ==5710==    by 0x44BCBA: do_one_ref (refs.c:527)
    ==5710==    by 0x44D240: do_for_each_ref_in_dir (refs.c:553)
    ==5710==    by 0x44D6BA: do_for_each_ref (refs.c:1298)
    ==5710==    by 0x410FE2: cgit_print_branches (ui-refs.c:191)
    ==5710==    by 0x4111E9: cgit_print_refs (ui-refs.c:244)
    ==5710==    by 0x407C85: refs_fn (cmd.c:105)
    ==5710==    by 0x405DDF: process_request (cgit.c:566)
    ==5710==
    ==5710== 6,846 (256 direct, 6,590 indirect) bytes in 1 blocks are definitely lost in loss record 68 of 71
    ==5710==    at 0x4C2C25E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
    ==5710==    by 0x46CA9B: xrealloc (wrapper.c:100)
    ==5710==    by 0x40AAA6: cgit_add_ref (shared.c:156)
    ==5710==    by 0x40ABC4: cgit_refs_cb (shared.c:186)
    ==5710==    by 0x44BCBA: do_one_ref (refs.c:527)
    ==5710==    by 0x44D240: do_for_each_ref_in_dir (refs.c:553)
    ==5710==    by 0x44D6EC: do_for_each_ref (refs.c:1288)
    ==5710==    by 0x4110D5: cgit_print_tags (ui-refs.c:218)
    ==5710==    by 0x4111FD: cgit_print_refs (ui-refs.c:246)
    ==5710==    by 0x407C85: refs_fn (cmd.c:105)
    ==5710==    by 0x405DDF: process_request (cgit.c:566)
    ==5710==    by 0x407490: cache_process (cache.c:322)

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>

cgit.h

@@ -304,6 +304,7 @@ extern char *strlpart(char *txt, int maxlen);
 extern char *strrpart(char *txt, int maxlen);
 
 extern void cgit_add_ref(struct reflist *list, struct refinfo *ref);
+extern void cgit_free_reflist_inner(struct reflist *list);
 extern int cgit_refs_cb(const char *refname, const unsigned char *sha1,
 			int flags, void *cb_data);
 

shared.c

@@ -176,6 +176,42 @@ static struct refinfo *cgit_mk_refinfo(const char *refname, const unsigned char
 	return ref;
 }
 
+static void cgit_free_taginfo(struct taginfo *tag)
+{
+	if (tag->tagger)
+		free(tag->tagger);
+	if (tag->tagger_email)
+		free(tag->tagger_email);
+	if (tag->msg)
+		free(tag->msg);
+	free(tag);
+}
+
+static void cgit_free_refinfo(struct refinfo *ref)
+{
+	if (ref->refname)
+		free((char *)ref->refname);
+	switch (ref->object->type) {
+	case OBJ_TAG:
+		cgit_free_taginfo(ref->tag);
+		break;
+	case OBJ_COMMIT:
+		cgit_free_commitinfo(ref->commit);
+		break;
+	}
+	free(ref);
+}
+
+void cgit_free_reflist_inner(struct reflist *list)
+{
+	int i;
+
+	for (i = 0; i < list->count; i++) {
+		cgit_free_refinfo(list->refs[i]);
+	}
+	free(list->refs);
+}
+
 int cgit_refs_cb(const char *refname, const unsigned char *sha1, int flags,
 		  void *cb_data)
 {

ui-refs.c

@@ -205,6 +205,8 @@ void cgit_print_branches(int maxcount)
 
 	if (maxcount < list.count)
 		print_refs_link("heads");
+
+	cgit_free_reflist_inner(&list);
 }
 
 void cgit_print_tags(int maxcount)
@@ -229,6 +231,8 @@ void cgit_print_tags(int maxcount)
 
 	if (maxcount < list.count)
 		print_refs_link("tags");
+
+	cgit_free_reflist_inner(&list);
 }
 
 void cgit_print_refs()