[meld] vc.git: Support showing (partially) staged status of files (bgo#755112)

[Kai Willadsen <kaiw src gnome org>]

commit 10c3e63e96fefe858e6860f878577b99f7c74086
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Oct 4 08:06:53 2015 +1000

    vc.git: Support showing (partially) staged status of files (bgo#755112)
    
    The use case here is that it's nice to know what you still need to look
    at, particularly in more complicated merges. We only differentiate
    between files that are unstaged, fully staged and partially staged.
    
    Actually having a real staging area view is an orthogonal consideration,
    and would still be nice.

 meld/vc/git.py |   25 +++++++++++++++++++++----
 1 files changed, 21 insertions(+), 4 deletions(-)
---
diff --git a/meld/vc/git.py b/meld/vc/git.py
index 4f4329c..8ef6c13 100644
--- a/meld/vc/git.py
+++ b/meld/vc/git.py
@@ -32,19 +32,23 @@ import shutil
 import subprocess
 import sys
 import tempfile
+from collections import defaultdict
 
 from meld.conf import _, ngettext
 
 from . import _vc
 
 
+NULL_SHA = "0000000000000000000000000000000000000000"
+
+
 class Vc(_vc.Vc):
 
     CMD = "git"
     NAME = "Git"
     VC_DIR = ".git"
 
-    GIT_DIFF_FILES_RE = ":(\d+) (\d+) [a-z0-9]+ [a-z0-9]+ ([XADMTU])\t(.*)"
+    GIT_DIFF_FILES_RE = ":(\d+) (\d+) ([a-z0-9]+) ([a-z0-9]+) ([XADMTU])\t(.*)"
     DIFF_RE = re.compile(GIT_DIFF_FILES_RE)
 
     conflict_map = {
@@ -127,7 +131,7 @@ class Vc(_vc.Vc):
         for p in paths:
             if os.path.isdir(p):
                 entries = self._get_modified_files(p)
-                names = [self.DIFF_RE.search(e).groups()[3] for e in entries]
+                names = [self.DIFF_RE.search(e).groups()[5] for e in entries]
                 files.extend(names)
             else:
                 files.append(os.path.relpath(p, self.root))
@@ -298,15 +302,28 @@ class Vc(_vc.Vc):
             # to STATE_NORMAL.
             self._tree_cache[get_real_path(path)] = _vc.STATE_NORMAL
         else:
+            tree_meta_cache = defaultdict(list)
+            staged = set()
+            unstaged = set()
+
             for entry in entries:
                 columns = self.DIFF_RE.search(entry).groups()
-                old_mode, new_mode, statekey, path = columns
+                old_mode, new_mode, old_sha, new_sha, statekey, path = columns
                 state = self.state_map.get(statekey.strip(), _vc.STATE_NONE)
                 self._tree_cache[get_real_path(path)] = state
                 if old_mode != new_mode:
                     msg = _("Mode changed from %s to %s" %
                             (old_mode, new_mode))
-                    self._tree_meta_cache[path] = msg
+                    tree_meta_cache[path].append(msg)
+                collection = unstaged if new_sha == NULL_SHA else staged
+                collection.add(path)
+
+            for path in staged:
+                tree_meta_cache[path].append(
+                    _("Partially staged") if path in unstaged else _("Staged"))
+
+            for path, msgs in tree_meta_cache.items():
+                self._tree_meta_cache[get_real_path(path)] = "; ".join(msgs)
 
             for path in ignored_entries:
                 self._tree_cache[get_real_path(path)] = _vc.STATE_IGNORED