Pull in simplified version from @wkentaro

This version uses `git status --porcelain` instead of making
multiple calls to `git status`.

plugins/git-prompt/gitstatus.py

@@ -4,6 +4,7 @@ from __future__ import print_function
 # change this symbol to whatever you prefer
 prehash = ':'
 
+import subprocess
 from subprocess import Popen, PIPE
 
 import sys
@@ -17,20 +18,23 @@ if 'fatal: Not a git repository' in error_string:
 
 branch = branch.decode("utf-8").strip()[11:]
 
-res, err = Popen(['git','diff','--name-status'], stdout=PIPE, stderr=PIPE).communicate()
-err_string = err.decode('utf-8')
-if 'fatal' in err_string:
+# Get git status (staged, change, conflicts and untracked)
+try:
+    res = subprocess.check_output(['git', 'status', '--porcelain'])
+except subprocess.CalledProcessError:
     sys.exit(0)
-changed_files = [namestat[0] for namestat in res.decode("utf-8").splitlines()]
-staged_files = [namestat[0] for namestat in Popen(['git','diff', '--staged','--name-status'], stdout=PIPE).communicate()[0].splitlines()]
-nb_changed = len(changed_files) - changed_files.count('U')
-nb_U = staged_files.count('U')
-nb_staged = len(staged_files) - nb_U
-staged = str(nb_staged)
-conflicts = str(nb_U)
-changed = str(nb_changed)
-nb_untracked = len([0 for status in Popen(['git','status','--porcelain',],stdout=PIPE).communicate()[0].decode("utf-8").splitlines() if status.startswith('??')])
-untracked = str(nb_untracked)
+status = [(st[0], st[1], st[2:]) for st in res.splitlines()]
+untracked, staged, changed, conflicts = [], [], [], []
+for st in status:
+    if st[0] == '?' and st[1] == '?':
+        untracked.append(st)
+    else:
+        if st[1] == 'M':
+            changed.append(st)
+        if st[0] == 'U':
+            conflicts.append(st)
+        elif st[0] != ' ':
+            staged.append(st)
 
 ahead, behind = 0,0
 
@@ -56,10 +60,10 @@ out = ' '.join([
     branch,
     str(ahead),
     str(behind),
-	staged,
-	conflicts,
-	changed,
-	untracked,
+    str(len(staged)),
+    str(len(conflicts)),
+    str(len(changed)),
+    str(len(untracked)),
 ])
 print(out, end='')