track: provide an option to handle paths literally

bk2204 · bk2204 · commit fc421da1c176 · 2019-08-06T21:53:32.000Z
Normally, the arguments to "git lfs track" are taken as glob patterns.
This is generally useful, but sometimes there are filenames that contain
special characters. Add a "--filename" option that forces arguments to
be taken as literal paths instead of glob patterns to make handling
these files easier.

In the test helpers, pass -F to grep so that our unusual file names
don't trigger undesired pattern matching. This has no effect on other
tests, as they all pass a literal filename here.
diff --git a/commands/command_track.go b/commands/command_track.go
@@ -27,6 +27,7 @@ var (
 	trackDryRunFlag         bool
 	trackNoModifyAttrsFlag  bool
 	trackNoExcludedFlag     bool
+	trackFilenameFlag       bool
 )
 
 func trackCommand(cmd *cobra.Command, args []string) {
@@ -95,6 +96,13 @@ ArgsLoop:
 			lockableArg = " " + git.LockableAttrib
 		}
 
+		if trackFilenameFlag {
+			// We need to do this after escapeAttrPattern since that
+			// function turns backslashes into slashes.
+			encodedArg = escapeGlobCharacters(encodedArg)
+			pattern = escapeGlobCharacters(pattern)
+		}
+
 		changedAttribLines[pattern] = fmt.Sprintf("%s filter=lfs diff=lfs merge=lfs -text%v%s", encodedArg, lockableArg, lineEnd)
 
 		if trackLockableFlag {
@@ -290,8 +298,16 @@ var (
 		" ": "[[:space:]]",
 		"#": "\\#",
 	}
+	trackEscapeStrings = []string{"*", "[", "]", "?"}
 )
 
+func escapeGlobCharacters(s string) string {
+	for _, ch := range trackEscapeStrings {
+		s = strings.Replace(s, ch, fmt.Sprintf("\\%s", ch), -1)
+	}
+	return s
+}
+
 func escapeAttrPattern(unescaped string) string {
 	var escaped string = strings.Replace(unescaped, `\`, "/", -1)
 
@@ -320,5 +336,6 @@ func init() {
 		cmd.Flags().BoolVarP(&trackDryRunFlag, "dry-run", "d", false, "preview results of running `git lfs track`")
 		cmd.Flags().BoolVarP(&trackNoModifyAttrsFlag, "no-modify-attrs", "", false, "skip modifying .gitattributes file")
 		cmd.Flags().BoolVarP(&trackNoExcludedFlag, "no-excluded", "", false, "skip listing excluded paths")
+		cmd.Flags().BoolVarP(&trackFilenameFlag, "filename", "", false, "treat this pattern as a literal filename")
 	})
 }
diff --git a/docs/man/git-lfs-track.1.ronn b/docs/man/git-lfs-track.1.ronn
@@ -31,6 +31,11 @@ to match paths.
 
   Disabled by default.
 
+* `--filename`
+  Treat the arguments as literal filenames, not as patterns. Any special glob
+  characters in the filename will be escaped when writing the `.gitattributes`
+  file.
+
 * `--lockable` `-l`
   Make the paths 'lockable', meaning they should be locked to edit them, and
   will be made read-only in the working copy when not locked.
diff --git a/t/t-track.sh b/t/t-track.sh
@@ -653,3 +653,31 @@ begin_test "track: escaped pattern in .gitattributes"
   fi
 )
 end_test
+
+begin_test "track: escaped glob pattern in .gitattributes"
+(
+  set -e
+
+  # None of these characters are valid in the Win32 subsystem.
+  [ "$IS_WINDOWS" -eq 1 ] && exit 0
+
+  reponame="track-escaped-glob"
+  git init "$reponame"
+  cd "$reponame"
+
+  filename='*[foo]bar?.txt'
+  contents='I need escaping'
+  contents_oid=$(calc_oid "$contents")
+
+  git lfs track --filename "$filename"
+  git add .
+  cat .gitattributes
+
+  printf "%s" "$contents" > "$filename"
+  git add .
+  git commit -m 'Add unusually named file'
+
+  # If Git understood our escaping, we'll have a pointer. Otherwise, we won't.
+  assert_pointer "master" "$filename" "$contents_oid" 15
+)
+end_test
diff --git a/t/testhelpers.sh b/t/testhelpers.sh
@@ -14,7 +14,7 @@ assert_pointer() {
     while read -r -d $'\0' x; do
       echo $x
     done |
-    grep "$path" | cut -f 3 -d " ")
+    grep -F "$path" | cut -f 3 -d " ")
 
   actual=$(git cat-file -p $gitblob)
   expected=$(pointer $oid $size)
