commands/{un,}track: local-prefix agnostic comparison

This patch use the trimCurrentPrefix utility introduced in the previous
patch to make all .gitattributes comparisons agnostic to the
"current-prefix" of "./" or ".\".

Since we treat both sides of the comparison as having passed through
"trimCurrentPrefix", we harden ourselves against "legacy"-style
.gitattributes patterns containing prefixes, and "modern"-style ones
lacking prefixes.

That means that both combinations of "git lfs untrack ./a.dat" and "git
lfs untrack a.dat" will remove both of these lines from a .gittatributes
file:

  ./a.dat filter=lfs ...
  a.dat filter=lfs ...

Signed-off-by: Taylor Blau <me@ttaylorr.com>

commands/command_track.go

@@ -67,7 +67,7 @@ func trackCommand(cmd *cobra.Command, args []string) {
 	var writeablePatterns []string
 ArgsLoop:
 	for _, unsanitizedPattern := range args {
-		pattern := cleanRootPath(unsanitizedPattern)
+		pattern := trimCurrentPrefix(cleanRootPath(unsanitizedPattern))
 		if !trackNoModifyAttrsFlag {
 			for _, known := range knownPatterns {
 				if known.Path == filepath.Join(relpath, pattern) &&

commands/command_untrack.go

@@ -63,8 +63,9 @@ func untrackCommand(cmd *cobra.Command, args []string) {
 }
 
 func removePath(path string, args []string) bool {
+	withoutCurrentDir := trimCurrentPrefix(path)
 	for _, t := range args {
-		if path == escapeAttrPattern(t) {
+		if withoutCurrentDir == escapeAttrPattern(trimCurrentPrefix(t)) {
 			return true
 		}
 	}

test/test-track.sh

@@ -540,3 +540,21 @@ begin_test "track (with comments)"
   [ "0" -eq "$(grep -c "\.png" track.log)" ]
 )
 end_test
+
+begin_test "track (with current-directory prefix)"
+(
+  set -e
+
+  reponame="track-with-current-directory-prefix"
+  git init "$reponame"
+  cd "$reponame"
+
+  git lfs track "./a.dat"
+  printf "a" > a.dat
+
+  git add .gitattributes a.dat
+  git commit -m "initial commit"
+
+  grep -e "^a.dat" .gitattributes
+)
+end_test

test/test-untrack.sh

@@ -72,3 +72,65 @@ begin_test "untrack removes escape sequences"
   assert_attributes_count "\\#" "filter=lfs" 0
 )
 end_test
+
+begin_test "untrack removes prefixed patterns (legacy)"
+(
+  set -e
+
+  reponame="untrack-removes-prefix-patterns-legacy"
+  git init "$reponame"
+  cd "$reponame"
+
+  echo "./a.dat filter=lfs diff=lfs merge=lfs" > .gitattributes
+  printf "a" > a.dat
+  git add .gitattributes a.dat
+  git commit -m "initial commit"
+
+  git lfs untrack "./a.dat"
+
+  if [ ! -z "$(cat .gitattributes)" ]; then
+    echo &>2 "fatal: expected 'git lfs untrack' to clear .gitattributes"
+    exit 1
+  fi
+
+  git checkout -- .gitattributes
+
+  git lfs untrack "a.dat"
+
+  if [ ! -z "$(cat .gitattributes)" ]; then
+    echo &>2 "fatal: expected 'git lfs untrack' to clear .gitattributes"
+    exit 1
+  fi
+)
+end_test
+
+begin_test "untrack removes prefixed patterns (modern)"
+(
+  set -e
+
+  reponame="untrack-removes-prefix-patterns-modern"
+  git init "$reponame"
+  cd "$reponame"
+
+  echo "a.dat filter=lfs diff=lfs merge=lfs" > .gitattributes
+  printf "a" > a.dat
+  git add .gitattributes a.dat
+  git commit -m "initial commit"
+
+  git lfs untrack "./a.dat"
+
+  if [ ! -z "$(cat .gitattributes)" ]; then
+    echo &>2 "fatal: expected 'git lfs untrack' to clear .gitattributes"
+    exit 1
+  fi
+
+  git checkout -- .gitattributes
+
+  git lfs untrack "a.dat"
+
+  if [ ! -z "$(cat .gitattributes)" ]; then
+    echo &>2 "fatal: expected 'git lfs untrack' to clear .gitattributes"
+    exit 1
+  fi
+)
+end_test