From 4c4929acadbd935a1207c8cb0e36b9602d2fce01 Mon Sep 17 00:00:00 2001
From: Anton Bobov <anton@bobov.name>
Date: Fri, 31 Oct 2025 21:53:57 +0500
Subject: [PATCH] Fix fixup's false filename detection in hunks containing
 dashed lines

The existing diff parser incorrectly treated subsequent lines beginning
with "---" as filename headers while processing hunks.  This caused
corruption when dashed lines appeared within diffs themselves.

Restrict filename detection to only occur between hunks.
---
 pkg/gui/controllers/helpers/fixup_helper.go   |  2 +-
 .../controllers/helpers/fixup_helper_test.go  | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/pkg/gui/controllers/helpers/fixup_helper.go b/pkg/gui/controllers/helpers/fixup_helper.go
index f44c23da8b4..a435d188dbb 100644
--- a/pkg/gui/controllers/helpers/fixup_helper.go
+++ b/pkg/gui/controllers/helpers/fixup_helper.go
@@ -194,7 +194,7 @@ func parseDiff(diff string) ([]*hunk, []*hunk) {
 		if strings.HasPrefix(line, "diff --git") {
 			finishHunk()
 			currentHunk = nil
-		} else if strings.HasPrefix(line, "--- ") {
+		} else if currentHunk == nil && strings.HasPrefix(line, "--- ") {
 			// For some reason, the line ends with a tab character if the file
 			// name contains spaces
 			filename = strings.TrimRight(line[6:], "\t")
diff --git a/pkg/gui/controllers/helpers/fixup_helper_test.go b/pkg/gui/controllers/helpers/fixup_helper_test.go
index 954161cd16a..e50a4249f70 100644
--- a/pkg/gui/controllers/helpers/fixup_helper_test.go
+++ b/pkg/gui/controllers/helpers/fixup_helper_test.go
@@ -78,6 +78,26 @@ index 9ce8efb33..fb5e469e7 100644
 				},
 			},
 		},
+		{
+			name: "hunk with dashed lines",
+			diff: `
+diff --git a/file1.txt b/file1.txt
+index 9ce8efb33..fb5e469e7 100644
+--- a/file1.txt
++++ b/file1.txt
+@@ -3,1 +3,1 @@
+--- xxx
++-- yyy
+`,
+			expectedDeletedLineHunks: []*hunk{
+				{
+					filename:     "file1.txt",
+					startLineIdx: 3,
+					numLines:     1,
+				},
+			},
+			expectedAddedLineHunks: []*hunk{},
+		},
 		{
 			name: "several hunks in different files",
 			diff: `