Add .literal suffix to make all filenames representable

docs/FAQ.md

@@ -197,21 +197,12 @@ better than just having the correct dotfile contents.
 There are a number of criticisms of how chezmoi's source state is represented on
 disk:
 
-1. The source file naming system cannot handle all possible filenames.
-2. Not all possible file permissions can be represented.
-3. The long source file names are weird and verbose.
-4. Everything is in a single directory, which can end up containing many entries.
+1. Not all possible file permissions can be represented.
+2. The long source file names are weird and verbose.
+3. Everything is in a single directory, which can end up containing many entries.
 
 chezmoi's source state representation is a deliberate, practical compromise.
 
-Certain target filenames, for example `~/dot_example`, are incompatible with
-chezmoi's
-[attributes](https://github.com/twpayne/chezmoi/blob/master/docs/REFERENCE.md#source-state-attributes)
-used in the source state. In practice, dotfile filenames are unlikely to
-conflict with chezmoi's attributes. If this does cause a genuine problem for
-you, please [open an issue on
-GitHub](https://github.com/twpayne/chezmoi/issues/new/choose).
-
 The `dot_` attribute makes it transparent which dotfiles are managed by chezmoi
 and which files are ignored by chezmoi. chezmoi ignores all files and
 directories that start with `.` so no special whitelists are needed for version

docs/REFERENCE.md

@@ -394,9 +394,10 @@ to as "attributes":
 | `run_`       | Treat the contents as a script to run.                                         |
 | `symlink_`   | Create a symlink instead of a regular file.                                    |
 
-| Suffix  | Effect                                               |
-| ------- | ---------------------------------------------------- |
-| `.tmpl` | Treat the contents of the source file as a template. |
+| Suffix     | Effect                                               |
+| ---------- | ---------------------------------------------------- |
+| `.literal` | Stop parsing suffix attributes.                      |
+| `.tmpl`    | Treat the contents of the source file as a template. |
 
 Different target types allow different prefixes and suffixes. The order of
 prefixes is important.
@@ -410,9 +411,9 @@ prefixes is important.
 | Script        | File        | `run_`, `once_`, `before_` or `after_`                                | `.tmpl`          |
 | Symbolic link | File        | `symlink_`, `dot_`,                                                   | `.tmpl`          |
 
-The `literal_` prefix can appear anywhere and stop prefix attribute parsing.
-This permits filenames that would otherwise conflict with chezmoi's attributes
-to be represented.
+The `literal_` prefix and `.literal` suffix can appear anywhere and stop
+attribute parsing. This permits filenames that would otherwise conflict with
+chezmoi's attributes to be represented.
 
 In addition, if the source file is encrypted, the suffix `.age` (when age
 encryption is used) or `.asc` (when gpg encryption is used) is stripped. These

internal/chezmoi/attr.go

@@ -181,9 +181,15 @@ func parseFileAttr(sourceName, encryptedSuffix string) FileAttr {
 	if encrypted {
 		name = strings.TrimSuffix(name, encryptedSuffix)
 	}
-	if strings.HasSuffix(name, TemplateSuffix) {
+	switch {
+	case strings.HasSuffix(name, literalSuffix):
+		name = mustTrimSuffix(name, literalSuffix)
+	case strings.HasSuffix(name, TemplateSuffix):
 		name = mustTrimSuffix(name, TemplateSuffix)
 		template = true
+		if strings.HasSuffix(name, literalSuffix) {
+			name = mustTrimSuffix(name, literalSuffix)
+		}
 	}
 	return FileAttr{
 		TargetName: name,
@@ -256,6 +262,9 @@ func (fa FileAttr) SourceName(encryptedSuffix string) string {
 	default:
 		sourceName += fa.TargetName
 	}
+	if fileSuffixRegexp.MatchString(fa.TargetName) {
+		sourceName += literalSuffix
+	}
 	if fa.Template {
 		sourceName += TemplateSuffix
 	}

internal/chezmoi/attr_test.go

@@ -80,10 +80,13 @@ func TestFileAttr(t *testing.T) {
 		"dot_name",
 		"exact_name",
 		"literal_name",
+		"literal_name",
 		"modify_name",
+		"name.literal",
 		"name",
 		"run_name",
 		"symlink_name",
+		"template.tmpl",
 	}
 	require.NoError(t, combinator.Generate(&fas, struct {
 		Type       SourceFileTargetType
@@ -184,6 +187,7 @@ func TestFileAttrLiteral(t *testing.T) {
 		sourceName      string
 		encryptedSuffix string
 		fileAttr        FileAttr
+		nonCanonical    bool
 	}{
 		{
 			sourceName: "dot_file",
@@ -221,10 +225,50 @@ func TestFileAttrLiteral(t *testing.T) {
 				Type:       SourceFileTypeScript,
 			},
 		},
+		{
+			sourceName: "file.literal",
+			fileAttr: FileAttr{
+				TargetName: "file",
+				Type:       SourceFileTypeFile,
+			},
+			nonCanonical: true,
+		},
+		{
+			sourceName: "file.literal.literal",
+			fileAttr: FileAttr{
+				TargetName: "file.literal",
+				Type:       SourceFileTypeFile,
+			},
+		},
+		{
+			sourceName: "file.tmpl",
+			fileAttr: FileAttr{
+				TargetName: "file",
+				Type:       SourceFileTypeFile,
+				Template:   true,
+			},
+		},
+		{
+			sourceName: "file.tmpl.literal",
+			fileAttr: FileAttr{
+				TargetName: "file.tmpl",
+				Type:       SourceFileTypeFile,
+			},
+		},
+		{
+			sourceName: "file.tmpl.literal.tmpl",
+			fileAttr: FileAttr{
+				TargetName: "file.tmpl",
+				Type:       SourceFileTypeFile,
+				Template:   true,
+			},
+		},
 	} {
 		t.Run(tc.sourceName, func(t *testing.T) {
 			assert.Equal(t, tc.fileAttr, parseFileAttr(tc.sourceName, tc.encryptedSuffix))
-			assert.Equal(t, tc.sourceName, tc.fileAttr.SourceName(tc.encryptedSuffix))
+			if !tc.nonCanonical {
+				assert.Equal(t, tc.sourceName, tc.fileAttr.SourceName(tc.encryptedSuffix))
+			}
 		})
 	}
 }

internal/chezmoi/chezmoi.go

@@ -39,6 +39,7 @@ const (
 	privatePrefix    = "private_"
 	runPrefix        = "run_"
 	symlinkPrefix    = "symlink_"
+	literalSuffix    = ".literal"
 	TemplateSuffix   = ".tmpl"
 )
 
@@ -56,6 +57,7 @@ const (
 var (
 	dirPrefixRegexp  = regexp.MustCompile(`\A(dot|exact|literal|private)_`)
 	filePrefixRegexp = regexp.MustCompile(`\A(after|before|create|dot|empty|encrypted|executable|literal|modify|once|private|run|symlink)_`)
+	fileSuffixRegexp = regexp.MustCompile(`\.(literal|tmpl)\z`)
 )
 
 // knownPrefixedFiles is a set of known filenames with the .chezmoi prefix.

internal/cmd/testdata/scripts/literal.txt

@@ -1,13 +1,15 @@
 # test that chezmoi add can add files that look like files in the source state
-chezmoi add $HOME${/}dot_file $HOME${/}run_script $HOME${/}symlink_symlink
-rm $HOME/dot_file $HOME/run_script $HOME/symlink_symlink
+chezmoi add $HOME${/}dot_file $HOME${/}run_script $HOME${/}symlink_symlink $HOME${/}template.tmpl
+rm $HOME/dot_file $HOME/run_script $HOME/symlink_symlink $HOME/template.tmpl
 chezmoi apply --force
 ! exists $HOME/.file
 ! stdout .
 ! exists $HOME/symlink
+! exists $HOME/template
 cmp $HOME/dot_file golden/dot_file
 cmp $HOME/run_script golden/run_script
 cmp $HOME/symlink_symlink golden/symlink_symlink
+cmp $HOME/template.tmpl golden/template.tmpl
 
 -- home/user/dot_file --
 # contents of dot_file
@@ -17,6 +19,8 @@ cmp $HOME/symlink_symlink golden/symlink_symlink
 echo contents of run_script
 -- home/user/symlink_symlink --
 # contents of symlink_symlink
+-- home/user/template.tmpl --
+# contents of template.tmpl
 -- golden/dot_file --
 # contents of dot_file
 -- golden/run_script --
@@ -25,3 +29,5 @@ echo contents of run_script
 echo contents of run_script
 -- golden/symlink_symlink --
 # contents of symlink_symlink
+-- golden/template.tmpl --
+# contents of template.tmpl