range-diff: plug memory leak in common invocation

avar · gitster · commit 4998e93fa6e0 · 2022-03-04T13:24:19.000-08:00
Create a public release_patch() version of the private free_patch() function added in 13b5af2 (apply: move libified code from builtin/apply.c to apply.{c,h}, 2016-04-22). Unlike the existing function this one doesn't free() the "struct patch" itself, so we can use it for variables on the stack. Use it in range-diff.c to fix a memory leak in common range-diff invocations, e.g.: git -P range-diff origin/master origin/next origin/seen Would emit several errors when compiled with SANITIZE=leak, but now runs cleanly. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/apply.c b/apply.c
@@ -219,13 +219,18 @@ static void free_fragment_list(struct fragment *list)
 	}
 }
 
-static void free_patch(struct patch *patch)
+void release_patch(struct patch *patch)
 {
 	free_fragment_list(patch->fragments);
 	free(patch->def_name);
 	free(patch->old_name);
 	free(patch->new_name);
 	free(patch->result);
+}
+
+static void free_patch(struct patch *patch)
+{
+	release_patch(patch);
 	free(patch);
 }
 
diff --git a/apply.h b/apply.h
@@ -173,6 +173,8 @@ int parse_git_diff_header(struct strbuf *root,
 			  unsigned int size,
 			  struct patch *patch);
 
+void release_patch(struct patch *patch);
+
 /*
  * Some aspects of the apply behavior are controlled by the following
  * bits in the "options" parameter passed to apply_all_patches().
diff --git a/range-diff.c b/range-diff.c
@@ -165,6 +165,7 @@ static int read_patches(const char *range, struct string_list *list,
 					    patch.old_mode, patch.new_mode);
 
 			strbuf_addstr(&buf, " ##");
+			release_patch(&patch);
 		} else if (in_header) {
 			if (starts_with(line, "Author: ")) {
 				strbuf_addstr(&buf, " ## Metadata ##\n");

Original file line number	Diff line number	Diff line change
`@@ -219,13 +219,18 @@ static void free_fragment_list(struct fragment *list)`
`219`	`219`	`}`
`220`	`220`	`}`
`221`	`221`
`222`		`-static void free_patch(struct patch *patch)`
	`222`	`+void release_patch(struct patch *patch)`
`223`	`223`	`{`
`224`	`224`	`free_fragment_list(patch->fragments);`
`225`	`225`	`free(patch->def_name);`
`226`	`226`	`free(patch->old_name);`
`227`	`227`	`free(patch->new_name);`
`228`	`228`	`free(patch->result);`
	`229`	`+}`
	`230`	`+`
	`231`	`+static void free_patch(struct patch *patch)`
	`232`	`+{`
	`233`	`+ release_patch(patch);`
`229`	`234`	`free(patch);`
`230`	`235`	`}`
`231`	`236`