[meld] Correctly start merge mode with output file for non-auto merges

[Kai Willadsen <kaiw src gnome org>]

commit c300c6e6e1cf08fd674a78ced90d196ba95f398b
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Wed Mar 13 06:35:58 2013 +1000

    Correctly start merge mode with output file for non-auto merges

 meld/filediff.py   |   11 ++++++++---
 meld/meldwindow.py |    6 ++++--
 2 files changed, 12 insertions(+), 5 deletions(-)
---
diff --git a/meld/filediff.py b/meld/filediff.py
index 61541b9..b12d04f 100644
--- a/meld/filediff.py
+++ b/meld/filediff.py
@@ -936,8 +936,10 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
     def set_merge_output_file(self, filename):
         if len(self.textbuffer) < 2:
             return
-        self.textbuffer[1].data.savefile = os.path.abspath(filename)
-        self.textbuffer[1].data.set_label(filename)
+        buf = self.textbuffer[1]
+        buf.data.savefile = os.path.abspath(filename)
+        buf.data.set_label(filename)
+        self.set_buffer_writable(buf, os.access(buf.data.savefile, os.W_OK))
         self.fileentry[1].set_filename(os.path.abspath(filename))
         self.recompute_label()
 
@@ -1061,7 +1063,10 @@ class FileDiff(melddoc.MeldDoc, gnomeglade.Component):
                             nextbit = nextbit[0:-1]
                         t.buf.insert(t.buf.get_end_iter(), nextbit)
                     else:
-                        writable = os.access(t.filename, os.W_OK)
+                        if t.buf.data.savefile:
+                            writable = os.access(t.buf.data.savefile, os.W_OK)
+                        else:
+                            writable = os.access(t.filename, os.W_OK)
                         self.set_buffer_writable(t.buf, writable)
                         t.buf.data.encoding = t.codec[0]
                         if hasattr(t.file, "newlines"):
diff --git a/meld/meldwindow.py b/meld/meldwindow.py
index 5f356f6..f6bf479 100644
--- a/meld/meldwindow.py
+++ b/meld/meldwindow.py
@@ -622,11 +622,13 @@ class MeldWindow(gnomeglade.Component):
             doc.on_button_diff_clicked(None)
         return doc
 
-    def append_filediff(self, files):
+    def append_filediff(self, files,  merge_output=None):
         assert len(files) in (1, 2, 3)
         doc = filediff.FileDiff(app.prefs, len(files))
         self._append_page(doc, "text-x-generic")
         doc.set_files(files)
+        if merge_output is not None:
+            doc.set_merge_output_file(merge_output)
         return doc
 
     def append_filemerge(self, files, merge_output=None):
@@ -666,7 +668,7 @@ class MeldWindow(gnomeglade.Component):
         elif auto_merge:
             return self.append_filemerge(paths, merge_output=merge_output)
         else:
-            return self.append_filediff(paths)
+            return self.append_filediff(paths, merge_output=merge_output)
 
     def append_vcview(self, location, auto_compare=False):
         doc = vcview.VcView(app.prefs)