Integrate Rüdiger Sonderfeld's code for detecting conflicted files under git.

lisp/ChangeLog

@@ -1,3 +1,10 @@
+2014-08-13  Eric S. Raymond  <esr@thyrsus.com>
+
+	* vc/vc-git.el (vc-git-conflicted-files): Integrate Rüdiger
+	Sonderfeld's code for detecting conflicted files using a status
+	listing.  Useful in itself and a step towards better smerge
+	support.
+
 2014-08-12  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* mpc.el (mpc-reorder): Don't bother splitting the "active"s elements

lisp/vc/vc-git.el

@@ -102,6 +102,7 @@
 ;; - delete-file (file)                            OK
 ;; - rename-file (old new)                         OK
 ;; - find-file-hook ()                             NOT NEEDED
+;; - conflicted-files                              OK
 
 ;;; Code:
 
@@ -769,6 +770,23 @@ This prompts for a branch to merge from."
     (with-current-buffer buffer (vc-run-delayed (vc-compilation-mode 'git)))
     (vc-set-async-update buffer)))
 
+(defun vc-git-conflicted-files (directory)
+  "Return the list of files with conflicts in DIRECTORY."
+  (let* ((status
+          (vc-git--run-command-string directory "status" "--porcelain" "--"))
+         (lines (split-string status "\n" 'omit-nulls))
+         files)
+    (dolist (line lines files)
+      (when (string-match "\\([ MADRCU?!][ MADRCU?!]\\) \\(.+\\)\\(?: -> \\(.+\\)\\)?"
+                          line)
+        (let ((state (match-string 1 line))
+              (file (match-string 2 line)))
+          ;; See git-status(1).
+          (when (member state '("AU" "UD" "UA" ;; "DD"
+                                "DU" "AA" "UU"))
+            (push file files)))))))
+
+
 ;;; HISTORY FUNCTIONS
 
 (autoload 'vc-setup-buffer "vc-dispatcher")