[PATCH 1 of 2 default] ui: allow open editor with custom filename

[Mykola Nikishov]

# HG changeset patch
# User Mykola Nikishov <mn at mn.com.ua>
# Date 1448136249 -7200
#      Sat Nov 21 22:04:09 2015 +0200
# Node ID 66cd5f930a40b3ea2a53e75600e9ffc18f093ce4
# Parent  61fbf5dc12b23e7a2a30cf04ebd9f096c42a1f61
ui: allow open editor with custom filename

By default, editor will use temp file named after hard-coded pattern
'hg-editor-XXX.txt' which makes it impossible for extensions to use
another filename if desired.

Now the middle part of the pattern ('editor') can be changed by
setting extra['prefix'].

diff -r 61fbf5dc12b2 -r 66cd5f930a40 mercurial/ui.py
--- a/mercurial/ui.py	Tue Nov 24 21:41:12 2015 +0000
+++ b/mercurial/ui.py	Sat Nov 21 22:04:09 2015 +0200
@@ -837,10 +837,12 @@
             self.write(*msg, **opts)
 
     def edit(self, text, user, extra=None, editform=None, pending=None):
-        if extra is None:
-            extra = {}
-        (fd, name) = tempfile.mkstemp(prefix="hg-editor-", suffix=".txt",
-                                      text=True)
+        extra_defaults = { 'prefix': 'editor' }
+        if extra is not None:
+            extra_defaults.update(extra)
+        extra = extra_defaults
+        (fd, name) = tempfile.mkstemp(prefix='hg-' + extra['prefix'] + '-',
+                                      suffix=".txt", text=True)
         try:
             f = os.fdopen(fd, "w")
             f.write(text)