Add integration test

The test would fail without the fixes in the previous commits; even if
only one of the configs is set.

pkg/integration/tests/patch_building/move_to_index_works_even_if_noprefix_is_set.go

@@ -0,0 +1,50 @@
+package patch_building
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var MoveToIndexWorksEvenIfNoprefixIsSet = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Moving a patch to the index works even if diff.noprefix or diff.external are set",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFileAndAdd("file1", "file1 content\n")
+		shell.Commit("first commit")
+
+		// Test that this works even if custom diff options are set
+		shell.SetConfig("diff.noprefix", "true")
+		shell.SetConfig("diff.external", "echo")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("first commit").IsSelected(),
+			).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			Lines(
+				Contains("file1").IsSelected(),
+			).
+			PressPrimaryAction()
+
+		t.Views().PatchBuildingSecondary().Content(Contains("+file1 content"))
+
+		t.Common().SelectPatchOption(Contains("Move patch out into index"))
+
+		t.Views().CommitFiles().IsFocused().
+			Lines(
+				Equals("(none)"),
+			)
+
+		t.Views().Files().
+			Lines(
+				Contains("A").Contains("file1"),
+			)
+	},
+})

pkg/integration/tests/test_list.go

@@ -204,6 +204,7 @@ var tests = []*components.IntegrationTest{
 	patch_building.MoveToIndexPartOfAdjacentAddedLines,
 	patch_building.MoveToIndexPartial,
 	patch_building.MoveToIndexWithConflict,
+	patch_building.MoveToIndexWorksEvenIfNoprefixIsSet,
 	patch_building.MoveToLaterCommit,
 	patch_building.MoveToLaterCommitPartialHunk,
 	patch_building.MoveToNewCommit,