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

[PATCH v3] diff: make diff_free_filespec_data accept NULL

From
Jinoh Kang <luke1337@theori.io>
Date
Nov 6, 2020, 17:14 UTC
Message-ID
<a096d122-52a3-700a-3a14-30a81b099cd8@theori.io>
In-Reply-To
<a0513d6f-1f69-683d-d6c5-75b17b8b6890@theori.io>

Commit 3aef54e8b8 ("diff: munmap() file contents before running external diff") introduced calls to diff_free_filespec_data in run_external_diff, which may pass NULL pointers.

Fix this and prevent any such bugs in the future by making `diff_free_filespec_data(NULL)` a no-op.

Fixes: 3aef54e8b8 ("diff: munmap() file contents before running external diff")
Signed-off-by: Jinoh Kang <luke1337@theori.io>
---
 diff.c              |  3 +++
 t/t7800-difftool.sh | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+)
diff --git a/diff.c b/diff.c
index d24f47df99..ace4a1d387 100644
--- a/diff.c
+++ b/diff.c
@@ -4115,6 +4115,9 @@ void diff_free_filespec_blob(struct diff_filespec *s)
 
 void diff_free_filespec_data(struct diff_filespec *s)
 {
+	if (!s)
+		return;
+
 	diff_free_filespec_blob(s);
 	FREE_AND_NULL(s->cnt_data);
 }
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 524f30f7dc..e9391abb54 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -728,6 +728,29 @@ test_expect_success 'add -N and difftool -d' '
 	git difftool --dir-diff --extcmd ls
 '
 
+test_expect_success 'difftool --cached with unmerged files' '
+	test_when_finished git reset --hard &&
+	echo base >file &&
+	git add file &&
+	git commit -m base &&
+	git checkout -B conflict-a &&
+	git checkout -B conflict-b &&
+	git checkout conflict-a &&
+	echo conflict-a >>file &&
+	git add file &&
+	git commit -m conflict-a &&
+	git checkout conflict-b &&
+	echo conflict-b >>file &&
+	git add file &&
+	git commit -m conflict-b &&
+	git checkout master &&
+	git merge conflict-a &&
+	test_must_fail git merge conflict-b &&
+	: >expect &&
+	git difftool --cached --no-prompt >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'outside worktree' '
 	echo 1 >1 &&
 	echo 2 >2 &&
-- 
2.26.2
Previous: Jinoh KangNext: Johannes Schindelin
Message 2 of 15 in “diff: handle NULL filespecs in run_external_diff”
  1. diff: handle NULL filespecs in run_external_diffJinoh Kang, Nov 6, 2020
  2. diff: make diff_free_filespec_data accept NULLJinoh Kang, Nov 6, 2020
  3. Johannes SchindelinNov 10, 2020
  4. Jinoh KangNov 10, 2020
  5. Jinoh KangNov 10, 2020
  6. Junio C HamanoNov 10, 2020
  7. diff: make diff_free_filespec_data accept NULLJinoh Kang, Nov 10, 2020
  8. Johannes SchindelinNov 10, 2020
  9. Jinoh KangNov 11, 2020
  10. Johannes SchindelinNov 11, 2020
  11. Junio C HamanoNov 10, 2020
  12. diff: make diff_free_filespec_data accept NULLJinoh Kang, Nov 11, 2020
  13. Johannes SchindelinNov 11, 2020
  14. Junio C HamanoNov 11, 2020
  15. Junio C HamanoNov 6, 2020

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.