From 29fced6251928e6334fa15fd28bf2c198acd4cd4 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 26 Feb 2025 16:44:48 -0800
Subject: [PATCH 1/2] Count traditional diff pattern lines correctly
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This fixes a bug I introduced on Thu Sep 5 16:37:50 2024 -0700.
Problem reported by Petr Vaněk in:
https://lists.gnu.org/archive/html/bug-patch/2025-02/msg00017.html
* src/pch.c (another_hunk): Fix method for counting number
of lines in a traditional diff hunk.
---
 src/pch.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/pch.c b/src/pch.c
index 63c9a0c..d9f5c61 100644
--- a/src/pch.c
+++ b/src/pch.c
@@ -1765,9 +1765,10 @@ another_hunk (enum diff difftype, bool rev)
 	if (*s == ',') {
 	    idx_t last;
 	    s = scan_linenum (s + 1, &last);
-	    if (p_first >= IDX_MAX - p_ptrn_lines)
+	    ptrdiff_t diff = last - p_first;
+	    if (! (-1 <= diff && diff < IDX_MAX))
 	      malformed ();
-	    p_ptrn_lines += 1 - p_first;
+	    p_ptrn_lines = diff + 1;
 	}
 	else
 	    p_ptrn_lines = (*s != 'a');
-- 
2.45.3


From b3d0c933389208ccac795a1b517c5a8b11cc012e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Van=C4=9Bk?= <arkamar@gentoo.org>
Date: Wed, 26 Feb 2025 16:44:48 -0800
Subject: [PATCH 2/2] Regression in commit abe92e8010ab affecting MariaDB tests

I have disovered a regression in commit abe92e8010ab ("Prefer idx_t,
ptrdiff_t to lin") while I was running MariaDB tests. The regression is
related to a diff file [1], where the patch fails to apply it with
following error:

  patch: **** '---' expected at line 2 of patch

To illustrate the issue, I have attached a git patch containing a
testcase with simplified reproducer.

[1] https://github.com/MariaDB/server/blob/mariadb-10.6.21/mysql-test/suite/innodb/r/innodb-wl5522%2Cstrict_crc32.rdiff file
---
 tests/Makefile.am             |  1 +
 tests/regression-abe92e8010ab | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 tests/regression-abe92e8010ab

diff --git a/tests/Makefile.am b/tests/Makefile.am
index acb449a..8f1a248 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -57,6 +57,7 @@ TESTS = \
 	preserve-mode-and-timestamp \
 	quoted-filenames \
 	read-only-files \
+	regression-abe92e8010ab \
 	reject-format \
 	remember-backup-files \
 	remember-reject-files \
diff --git a/tests/regression-abe92e8010ab b/tests/regression-abe92e8010ab
new file mode 100644
index 0000000..0e11e34
--- /dev/null
+++ b/tests/regression-abe92e8010ab
@@ -0,0 +1,33 @@
+. $srcdir/test-lib.sh
+
+require cat
+use_local_patch
+use_tmpdir
+
+cat > f <<EOF
+1
+2
+test:
+a
+4
+EOF
+
+cat > f.diff <<EOF
+2,3c2
+< test:
+< a
+---
+> 3
+EOF
+
+check 'patch f < f.diff' <<EOF
+patching file f
+Hunk #1 succeeded at 3 (offset 1 line).
+EOF
+
+check 'cat f' <<EOF
+1
+2
+3
+4
+EOF
-- 
2.45.3