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

[PATCH] apply: fix new-style empty context line triggering incomplete-line check

From
Junio C Hamano <gitster@pobox.com>
Date
Mar 17, 2026, 18:01 UTC
Message-ID
<xmqqldfql4hp.fsf@gitster.g>

A new-style unified context diff represents an empty context line with an empty line (instead of a line with a single SP on it). The code to check whitespace errors in an incoming patch is designed to omit the first byte of a line (typically SP, "-", or "+") and pass the remainder of the line to the whitespace checker.

Usually we do not pass a context line to the whitespace error checker, but when we are correcting errors, we do. This "remove the first byte and send the remainder" strategy of checking a line ended up sending a zero-length string to the whitespace checker when seeing a new-style empty context line, which caused the whitespace checker to say "ah, you do not even have a newline at the end!", leading to an "incomplete line" in the middle of the patch!

Fix this by pretending that we got a traditional empty context line when we drive the whitespace checker.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 apply.c                  | 12 ++++++++++--
 t/t4124-apply-ws-rule.sh | 16 ++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)
diff --git a/apply.c b/apply.c
index f01204d15b..e88e5c77e3 100644
--- a/apply.c
+++ b/apply.c
@@ -1796,8 +1796,16 @@ static int parse_fragment(struct apply_state *state,
 			trailing++;
 			check_old_for_crlf(patch, line, len);
 			if (!state->apply_in_reverse &&
-			    state->ws_error_action == correct_ws_error)
-				check_whitespace(state, line, len, patch->ws_rule);
+			    state->ws_error_action == correct_ws_error) {
+				const char *test_line = line;
+				int test_len = len;
+				if (*line == '\n') {
+					test_line = " \n";
+					test_len = 2;
+				}
+				check_whitespace(state, test_line, test_len,
+						 patch->ws_rule);
+			}
 			break;
 		case '-':
 			if (!state->apply_in_reverse)
diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index 29ea7d4268..8573e12f46 100755
--- a/t/t4124-apply-ws-rule.sh
+++ b/t/t4124-apply-ws-rule.sh
@@ -561,6 +561,22 @@ test_expect_success 'check incomplete lines (setup)' '
 	git config core.whitespace incomplete-line
 '
 
+test_expect_success 'no incomplete context line (not an error)' '
+	test_when_finished "rm -f sample*-i patch patch-new target" &&
+	(test_write_lines 1 2 3 "" 4 5 ) >sample-i &&
+	(test_write_lines 1 2 3 "" 0 5 ) >sample2-i &&
+	cat sample-i >target &&
+	git add target &&
+	cat sample2-i >target &&
+	git diff-files -p target >patch &&
+	sed -e "s/^ $//" <patch >patch-new &&
+
+	cat sample-i >target &&
+	git apply --whitespace=fix <patch-new 2>error &&
+	test_cmp sample2-i target &&
+	test_must_be_empty error
+'
+
 test_expect_success 'incomplete context line (not an error)' '
 	(test_write_lines 1 2 3 4 5 && printf 6) >sample-i &&
 	(test_write_lines 1 2 3 0 5 && printf 6) >sample2-i &&
-- 
2.53.0-769-g8689fa97fd
Next: Eric Sunshine
Message 1 of 7 in “apply: fix new-style empty context line triggering incomplete-line check”
  1. apply: fix new-style empty context line triggering incomplete-line checkJunio C Hamano, Mar 17, 2026
  2. Eric SunshineMar 17, 2026
  3. Junio C HamanoMar 17, 2026
  4. D. Ben KnobleMar 18, 2026
  5. Eric SunshineMar 18, 2026
  6. Junio C HamanoMar 18, 2026
  7. Junio C HamanoMar 31, 2026

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.