From b366d0e1c3fd227a69a6e107e40b83d0dbb9e686 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Sat, 30 Mar 2024 18:36:11 +0000
Subject: [PATCH] fix: Fix panic when adding children in exact_ dirs

---
 internal/chezmoi/sourcestate.go               |  4 ++--
 internal/cmd/addcmd_test.go                   | 19 +++++++++++++++++++
 internal/cmd/testdata/scripts/issue3666.txtar |  7 +++++++
 3 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 internal/cmd/testdata/scripts/issue3666.txtar

diff --git a/internal/chezmoi/sourcestate.go b/internal/chezmoi/sourcestate.go
index 15538651a09..65aa01f0926 100644
--- a/internal/chezmoi/sourcestate.go
+++ b/internal/chezmoi/sourcestate.go
@@ -417,7 +417,7 @@ DEST_ABS_PATH:
 				switch sourceStateDir, ok := node.sourceStateEntry.(*SourceStateDir); {
 				case i != len(nodes)-1 && !ok:
 					panic(fmt.Errorf("nodes[%d]: unexpected non-terminal source state entry, got %T", i, node.sourceStateEntry))
-				case sourceStateDir.Attr.External:
+				case ok && sourceStateDir.Attr.External:
 					return fmt.Errorf("%s: cannot add entry in external_ directory", destAbsPath)
 				}
 			}
@@ -639,7 +639,7 @@ func (s *SourceState) AddDestAbsPathInfos(
 			return nil
 		}
 		parentRelPath := parentAbsPath.MustTrimDirPrefix(s.destDirAbsPath)
-		if s.root.get(parentRelPath) != nil {
+		if _, ok := s.root.get(parentRelPath).(*SourceStateDir); ok {
 			return nil
 		}
 
diff --git a/internal/cmd/addcmd_test.go b/internal/cmd/addcmd_test.go
index 91ffd89791b..fbc7a2c61de 100644
--- a/internal/cmd/addcmd_test.go
+++ b/internal/cmd/addcmd_test.go
@@ -237,6 +237,25 @@ func TestAddCmd(t *testing.T) {
 				),
 			},
 		},
+		{
+			name: "issue_3666",
+			root: map[string]any{
+				"/home/user": map[string]any{
+					".config/helix/themes/ayu_custom.toml": "# contents of ayu_custom.toml\n",
+					".local/share/chezmoi": map[string]any{
+						"dot_config/exact_helix": &vfst.Dir{Perm: 0o777 &^ chezmoitest.Umask},
+					},
+				},
+			},
+			args: []string{"~/.config/helix/themes/ayu_custom.toml"},
+			tests: []any{
+				vfst.TestPath("/home/user/.local/share/chezmoi/dot_config/exact_helix/themes/ayu_custom.toml",
+					vfst.TestModeIsRegular(),
+					vfst.TestModePerm(0o666&^chezmoitest.Umask),
+					vfst.TestContentsString("# contents of ayu_custom.toml\n"),
+				),
+			},
+		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			chezmoitest.SkipUnlessGOOS(t, tc.name)
diff --git a/internal/cmd/testdata/scripts/issue3666.txtar b/internal/cmd/testdata/scripts/issue3666.txtar
new file mode 100644
index 00000000000..deeae377d6d
--- /dev/null
+++ b/internal/cmd/testdata/scripts/issue3666.txtar
@@ -0,0 +1,7 @@
+# test that chezmoi add creates parent directories
+exec chezmoi add $HOME${/}.config/helix/themes/ayu_custom.toml
+exists $CHEZMOISOURCEDIR/dot_config/exact_helix/themes/ayu_custom.toml
+
+-- home/user/.config/helix/themes/ayu_custom.toml --
+# contents of ayu_custom.toml
+-- home/user/.local/share/chezmoi/dot_config/exact_helix/.keep --