amend: prevent loss of bookmark on failed amend

The active bookmark were moved to the temporary commit. When the transaction
were rollbacked, the bookmark were lost.

We now temporarly disable the bookmark to prevent this effect.

mercurial/cmdutil.py

@@ -1635,10 +1635,13 b' def amend(ui, repo, commitfunc, old, ext'
             # First, do a regular commit to record all changes in the working
             # directory (if there are any)
             ui.callhooks = False
+            currentbookmark = repo._bookmarkcurrent
             try:
+                repo._bookmarkcurrent = None
                 opts['message'] = 'temporary amend commit for %s' % old
                 node = commit(ui, repo, commitfunc, pats, opts)
             finally:
+                repo._bookmarkcurrent = currentbookmark
                 ui.callhooks = True
             ctx = repo[node]
 

tests/test-commit-amend.t

@@ -243,6 +243,24 b' Moving bookmarks, preserve active bookma'
      book1                     1:48bb6e53a15f
    * book2                     1:48bb6e53a15f
 
+abort does not loose bookmarks
+
+  $ cat > editor.sh << '__EOF__'
+  > #!/bin/sh
+  > echo "" > "$1"
+  > __EOF__
+  $ echo a >> a
+  $ HGEDITOR="\"sh\" \"`pwd`/editor.sh\"" hg commit --amend
+  transaction abort!
+  rollback completed
+  abort: empty commit message
+  [255]
+  $ hg book
+     book1                     1:48bb6e53a15f
+   * book2                     1:48bb6e53a15f
+  $ hg revert -Caq
+  $ rm editor.sh
+
   $ echo '[defaults]' >> $HGRCPATH
   $ echo "commit=-d '0 0'" >> $HGRCPATH