Add pathspec support in git-missing

Commands.md

@@ -1296,14 +1296,20 @@ Creates a zip archive of the current git repository. The name of the archive wil
 
 ## git missing
 
-Print out which commits are on one branch or the other but not both.
+Print out which commits are on one branch or the other but not both. Optionally, you can specify a path to limit the comparison to a specific directory or file.
 
 ```bash
 $ git missing master
 < d14b8f0 only on current checked out branch
 > 97ef387 only on master
 ```
 
+```bash
+$ git missing master -- src/
+< ed52989 only on current branch, in src/ directory
+> 7988c4b only on master, in src/ directory
+```
+
 ## git lock
 
 Lock a local file `filename`:

bin/git-missing

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 usage() {
-    echo 1>&2 "usage: git missing [<first branch>] <second branch> [<git log options>]"
+    echo 1>&2 "usage: git missing [<first branch>] <second branch> [<git log options>] [[--] <path>...]"
 }
 
 if [ "${#}" -lt 1 ]
@@ -12,16 +12,28 @@ fi
 
 declare -a git_log_args=()
 declare -a branches=()
+declare pathspec=""
+declare parse_path=false
+
 for arg in "$@" ; do
 
+    if [[ $parse_path == true ]]; then
+        pathspec="$*"
+        break
+    fi
+
     case "$arg" in
+        --)
+            parse_path=true
+            ;;
         --*)
             git_log_args+=( "$arg" )
             ;;
         *)
             branches+=( "$arg" )
             ;;
     esac
+    shift
 done
 
 firstbranch=
@@ -38,4 +50,8 @@ else
     exit 1
 fi
 
-git log "${git_log_args[@]}" "$firstbranch"..."$secondbranch" --format="%m %h %s" --left-right
+if [[ -n "$pathspec" ]]; then
+    git log "${git_log_args[@]}" "$firstbranch"..."$secondbranch" --format="%m %h %s" --left-right -- "$pathspec"
+else
+    git log "${git_log_args[@]}" "$firstbranch"..."$secondbranch" --format="%m %h %s" --left-right
+fi