Add integration test demonstrating whitespace loss in preserved commit messages

Typing a description with leading blank lines, canceling the commit panel, and
reopening it currently drops leading blank lines.

pkg/integration/tests/commit/preserve_commit_message_whitespace.go

@@ -0,0 +1,42 @@
+package commit
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var PreserveCommitMessageWhitespace = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Whitespace in the description (e.g. leading blank lines, indented first line) should be preserved when canceling and reopening the commit message panel",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFileAndAdd("myfile", "myfile content")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Files().
+			IsFocused().
+			Press(keys.Files.CommitChanges)
+
+		t.ExpectPopup().CommitMessagePanel().
+			Type("my commit message").
+			SwitchToDescription().
+			AddNewline().
+			AddNewline().
+			Type("body  ").
+			Cancel()
+
+		t.Views().Files().
+			IsFocused().
+			Press(keys.Files.CommitChanges)
+
+		t.ExpectPopup().CommitMessagePanel().
+			Content(Equals("my commit message")).
+			SwitchToDescription().
+			/* EXPECTED:
+			Content(Equals("\n\nbody  ")).
+			ACTUAL: */
+			Content(Equals("body")).
+			Cancel()
+	},
+})

pkg/integration/tests/test_list.go

@@ -142,6 +142,7 @@ var tests = []*components.IntegrationTest{
 	commit.PasteCommitMessage,
 	commit.PasteCommitMessageOverExisting,
 	commit.PreserveCommitMessage,
+	commit.PreserveCommitMessageWhitespace,
 	commit.ResetAuthor,
 	commit.ResetAuthorRange,
 	commit.Revert,