git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH 13/14] range-diff: plug memory leak in read_patches()

From
Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date
Mar 2, 2022, 17:10 UTC
Message-ID
<patch-13.14-e7b823f70c8-20220302T170718Z-avarab@gmail.com>
In-Reply-To
<cover-00.14-00000000000-20220302T170718Z-avarab@gmail.com>

Amend code added in d9c66f0b5bf (range-diff: first rudimentary implementation, 2018-08-13) to use a "goto cleanup" pattern. This makes for less code, and frees memory that we'd previously leak.

The reason for changing free(util) to FREE_AND_NULL(util) is because at the end of the function we append the contents of "util" to a "struct string_list" if it's non-NULL.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 range-diff.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)
diff --git a/range-diff.c b/range-diff.c
index b2a2961f521..b72eb9fdbee 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -40,6 +40,7 @@ static int read_patches(const char *range, struct string_list *list,
 	char *line, *current_filename = NULL;
 	ssize_t len;
 	size_t size;
+	int ret = -1;
 
 	strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
 		     "--reverse", "--date-order", "--decorate=no",
@@ -68,10 +69,10 @@ static int read_patches(const char *range, struct string_list *list,
 	if (strbuf_read(&contents, cp.out, 0) < 0) {
 		error_errno(_("could not read `log` output"));
 		finish_command(&cp);
-		return -1;
+		goto cleanup;
 	}
 	if (finish_command(&cp))
-		return -1;
+		goto cleanup;
 
 	line = contents.buf;
 	size = contents.len;
@@ -95,12 +96,9 @@ static int read_patches(const char *range, struct string_list *list,
 			CALLOC_ARRAY(util, 1);
 			if (get_oid(p, &util->oid)) {
 				error(_("could not parse commit '%s'"), p);
-				free(util);
-				free(current_filename);
+				FREE_AND_NULL(util);
 				string_list_clear(list, 1);
-				strbuf_release(&buf);
-				strbuf_release(&contents);
-				return -1;
+				goto cleanup;
 			}
 			util->matching = -1;
 			in_header = 1;
@@ -111,11 +109,8 @@ static int read_patches(const char *range, struct string_list *list,
 			error(_("could not parse first line of `log` output: "
 				"did not start with 'commit ': '%s'"),
 			      line);
-			free(current_filename);
 			string_list_clear(list, 1);
-			strbuf_release(&buf);
-			strbuf_release(&contents);
-			return -1;
+			goto cleanup;
 		}
 
 		if (starts_with(line, "diff --git")) {
@@ -136,12 +131,9 @@ static int read_patches(const char *range, struct string_list *list,
 			if (len < 0) {
 				error(_("could not parse git header '%.*s'"),
 				      orig_len, line);
-				free(util);
-				free(current_filename);
+				FREE_AND_NULL(util);
 				string_list_clear(list, 1);
-				strbuf_release(&buf);
-				strbuf_release(&contents);
-				return -1;
+				goto cleanup;
 			}
 			strbuf_addstr(&buf, " ## ");
 			if (patch.is_new > 0)
@@ -219,6 +211,9 @@ static int read_patches(const char *range, struct string_list *list,
 		strbuf_addch(&buf, '\n');
 		util->diffsize++;
 	}
+
+	ret = 0;
+cleanup:
 	strbuf_release(&contents);
 
 	if (util)
@@ -226,7 +221,7 @@ static int read_patches(const char *range, struct string_list *list,
 	strbuf_release(&buf);
 	free(current_filename);
 
-	return 0;
+	return ret;
 }
 
 static int patch_util_cmp(const void *dummy, const struct patch_util *a,
-- 
2.35.1.1228.g56895c6ee86
Previous: Ævar Arnfjörð BjarmasonNext: Derrick Stolee
Message 19 of 37 in “tree-wide: small fixes for memory leaks”
  1. 00/14 tree-wide: small fixes for memory leaksÆvar Arnfjörð Bjarmason, Mar 2, 2022
  2. 01/14 index-pack: fix memory leaksÆvar Arnfjörð Bjarmason, Mar 2, 2022
  3. Derrick StoleeMar 2, 2022
  4. Ævar Arnfjörð BjarmasonMar 3, 2022
  5. 02/14 merge-base: free() allocated "struct commit **" listÆvar Arnfjörð Bjarmason, Mar 2, 2022
  6. 03/14 diff.c: free "buf" in diff_words_flush()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  7. 05/14 remote-curl.c: free memory in cmd_main()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  8. 04/14 urlmatch.c: add and use a *_release() functionÆvar Arnfjörð Bjarmason, Mar 2, 2022
  9. 06/14 bundle: call strvec_clear() on allocated strvecÆvar Arnfjörð Bjarmason, Mar 2, 2022
  10. 08/14 submodule--helper: fix trivial leak in module_add()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  11. 07/14 transport: stop needlessly copying bundle header referencesÆvar Arnfjörð Bjarmason, Mar 2, 2022
  12. Derrick StoleeMar 2, 2022
  13. Ævar Arnfjörð BjarmasonMar 3, 2022
  14. 09/14 commit-graph: fix memory leak in misused string_list APIÆvar Arnfjörð Bjarmason, Mar 2, 2022
  15. 10/14 commit-graph: stop fill_oids_from_packs() progress on error and free()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  16. 11/14 lockfile API users: simplify and don't leak "path"Ævar Arnfjörð Bjarmason, Mar 2, 2022
  17. 12/14 range-diff: plug memory leak in common invocationÆvar Arnfjörð Bjarmason, Mar 2, 2022
  18. 14/14 repository.c: free the "path cache" in repo_clear()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  19. 13/14 range-diff: plug memory leak in read_patches()Ævar Arnfjörð Bjarmason, Mar 2, 2022
  20. Derrick StoleeMar 2, 2022
  21. 00/14 tree-wide: small fixes for memory leaksÆvar Arnfjörð Bjarmason, Mar 4, 2022
  22. 01/14 index-pack: fix memory leaksÆvar Arnfjörð Bjarmason, Mar 4, 2022
  23. 02/14 merge-base: free() allocated "struct commit **" listÆvar Arnfjörð Bjarmason, Mar 4, 2022
  24. 03/14 diff.c: free "buf" in diff_words_flush()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  25. 04/14 urlmatch.c: add and use a *_release() functionÆvar Arnfjörð Bjarmason, Mar 4, 2022
  26. 05/14 remote-curl.c: free memory in cmd_main()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  27. 06/14 bundle: call strvec_clear() on allocated strvecÆvar Arnfjörð Bjarmason, Mar 4, 2022
  28. 07/14 transport: stop needlessly copying bundle header referencesÆvar Arnfjörð Bjarmason, Mar 4, 2022
  29. Derrick StoleeMar 4, 2022
  30. 09/14 commit-graph: fix memory leak in misused string_list APIÆvar Arnfjörð Bjarmason, Mar 4, 2022
  31. 12/14 range-diff: plug memory leak in common invocationÆvar Arnfjörð Bjarmason, Mar 4, 2022
  32. 13/14 range-diff: plug memory leak in read_patches()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  33. 11/14 lockfile API users: simplify and don't leak "path"Ævar Arnfjörð Bjarmason, Mar 4, 2022
  34. 14/14 repository.c: free the "path cache" in repo_clear()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  35. 10/14 commit-graph: stop fill_oids_from_packs() progress on error and free()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  36. 08/14 submodule--helper: fix trivial leak in module_add()Ævar Arnfjörð Bjarmason, Mar 4, 2022
  37. Derrick StoleeMar 4, 2022

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.