From 981bc4b60c4490e10d9f8ca8cfd7833e303c399e Mon Sep 17 00:00:00 2001
From: Billy Keyes <bluekeyes@gmail.com>
Date: Mon, 26 Dec 2022 17:56:30 -0500
Subject: [PATCH] Fix parsing of mode lines with trailing space (#38)

If a patch is passed through a system that converts line endings to
'\r\n', mode lines end up with trailing whitespace that confuses
strconv.ParseInt. In Git, this is avoided by using strtoul() for parsing,
which stops at the first non-digit character.

Changing line endings in patch content itself will cause other problems
so it is best to avoid this transform, but if it does happen, it
shouldn't cause a parse error.
---
 gitdiff/file_header.go      |  4 ++--
 gitdiff/file_header_test.go | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/gitdiff/file_header.go b/gitdiff/file_header.go
index 58904b4..77ceb5d 100644
--- a/gitdiff/file_header.go
+++ b/gitdiff/file_header.go
@@ -324,12 +324,12 @@ func parseGitHeaderNewName(f *File, line, defaultName string) error {
 }
 
 func parseGitHeaderOldMode(f *File, line, defaultName string) (err error) {
-	f.OldMode, err = parseMode(line)
+	f.OldMode, err = parseMode(strings.TrimSpace(line))
 	return
 }
 
 func parseGitHeaderNewMode(f *File, line, defaultName string) (err error) {
-	f.NewMode, err = parseMode(line)
+	f.NewMode, err = parseMode(strings.TrimSpace(line))
 	return
 }
 
diff --git a/gitdiff/file_header_test.go b/gitdiff/file_header_test.go
index 102795c..ef29833 100644
--- a/gitdiff/file_header_test.go
+++ b/gitdiff/file_header_test.go
@@ -486,6 +486,12 @@ func TestParseGitHeaderData(t *testing.T) {
 				OldMode: os.FileMode(0100644),
 			},
 		},
+		"oldModeWithTrailingSpace": {
+			Line: "old mode 100644\r\n",
+			OutputFile: &File{
+				OldMode: os.FileMode(0100644),
+			},
+		},
 		"invalidOldMode": {
 			Line: "old mode rw\n",
 			Err:  true,
@@ -496,6 +502,12 @@ func TestParseGitHeaderData(t *testing.T) {
 				NewMode: os.FileMode(0100755),
 			},
 		},
+		"newModeWithTrailingSpace": {
+			Line: "new mode 100755\r\n",
+			OutputFile: &File{
+				NewMode: os.FileMode(0100755),
+			},
+		},
 		"invalidNewMode": {
 			Line: "new mode rwx\n",
 			Err:  true,
@@ -518,6 +530,15 @@ func TestParseGitHeaderData(t *testing.T) {
 				IsNew:   true,
 			},
 		},
+		"newFileModeWithTrailingSpace": {
+			Line:        "new file mode 100755\r\n",
+			DefaultName: "dir/file.txt",
+			OutputFile: &File{
+				NewName: "dir/file.txt",
+				NewMode: os.FileMode(0100755),
+				IsNew:   true,
+			},
+		},
 		"copyFrom": {
 			Line: "copy from dir/file.txt\n",
 			OutputFile: &File{