rebase: adds storing collapse message (issue4792)

Before this patch collapse message wasn't stored so when
you ran into the merge conflict while rebasing, running
rebase --continue didn't remember the message and
always opened editor to fill commit message.

This patch adds saving collapse message in
.hg/last-message.txt and restoring it later
when needed.

hgext/rebase.py

@@ -263,9 +263,11 b' def rebase(ui, repo, **opts):'
             try:
                 (originalwd, target, state, skipped, collapsef, keepf,
                  keepbranchesf, external, activebookmark) = restorestatus(repo)
+                collapsemsg = restorecollapsemsg(repo)
             except error.RepoLookupError:
                 if abortf:
                     clearstatus(repo)
+                    clearcollapsemsg(repo)
                     repo.ui.warn(_('rebase aborted (no revision is removed,'
                                    ' only broken state is cleared)\n'))
                     return 0
@@ -388,6 +390,7 b' def rebase(ui, repo, **opts):'
                                              targetancestors)
                 storestatus(repo, originalwd, target, state, collapsef, keepf,
                             keepbranchesf, external, activebookmark)
+                storecollapsemsg(repo, collapsemsg)
                 if len(repo[None].parents()) == 2:
                     repo.ui.debug('resuming interrupted rebase\n')
                 else:
@@ -509,6 +512,7 b' def rebase(ui, repo, **opts):'
                     # active bookmark was divergent one and has been deleted
                     activebookmark = None
         clearstatus(repo)
+        clearcollapsemsg(repo)
 
         ui.note(_("rebase completed\n"))
         util.unlinkpath(repo.sjoin('undo'), ignoremissing=True)
@@ -846,6 +850,29 b' def updatebookmarks(repo, targetnode, ns'
             bookmarks.deletedivergent(repo, [targetnode], k)
     marks.recordchange(tr)
 
+def storecollapsemsg(repo, collapsemsg):
+    'Store the collapse message to allow recovery'
+    collapsemsg = collapsemsg or ''
+    f = repo.vfs("last-message.txt", "w")
+    f.write("%s\n" % collapsemsg)
+    f.close()
+
+def clearcollapsemsg(repo):
+    'Remove collapse message file'
+    util.unlinkpath(repo.join("last-message.txt"), ignoremissing=True)
+
+def restorecollapsemsg(repo):
+    'Restore previously stored collapse message'
+    try:
+        f = repo.vfs("last-message.txt")
+        collapsemsg = f.readline().strip()
+        f.close()
+    except IOError as err:
+        if err.errno != errno.ENOENT:
+            raise
+        raise error.Abort(_('no rebase in progress'))
+    return collapsemsg
+
 def storestatus(repo, originalwd, target, state, collapse, keep, keepbranches,
                 external, activebookmark):
     'Store the current status to allow recovery'
@@ -1005,6 +1032,7 b' def abort(repo, originalwd, target, stat'
 
     finally:
         clearstatus(repo)
+        clearcollapsemsg(repo)
         repo.ui.warn(_('rebase aborted\n'))
     return 0
 

tests/test-rebase-collapse.t

@@ -804,3 +804,52 b' Test collapsing changes that add then re'
   base
 
   $ cd ..
+
+Test that rebase --collapse will remember message after
+running into merge conflict and invoking rebase --continue.
+
+  $ hg init collapse_remember_message
+  $ cd collapse_remember_message
+  $ touch a
+  $ hg add a
+  $ hg commit -m "a"
+  $ echo "a-default" > a
+  $ hg commit -m "a-default"
+  $ hg update -r 0
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg branch dev
+  marked working directory as branch dev
+  (branches are permanent and global, did you want a bookmark?)
+  $ echo "a-dev" > a
+  $ hg commit -m "a-dev"
+  $ hg rebase --collapse -m "a-default-dev" -d 1
+  rebasing 2:b8d8db2b242d "a-dev" (tip)
+  merging a
+  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
+  unresolved conflicts (see hg resolve, then hg rebase --continue)
+  [1]
+  $ rm a.orig
+  $ hg resolve --mark a
+  (no more unresolved files)
+  continue: hg rebase --continue
+  $ hg rebase --continue
+  rebasing 2:b8d8db2b242d "a-dev" (tip)
+  saved backup bundle to $TESTTMP/collapse_remember_message/.hg/strip-backup/b8d8db2b242d-f474c19a-backup.hg (glob)
+  $ hg log
+  changeset:   2:12bb766dceb1
+  tag:         tip
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     a-default-dev
+  
+  changeset:   1:3c8db56a44bc
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     a-default
+  
+  changeset:   0:3903775176ed
+  user:        test
+  date:        Thu Jan 01 00:00:00 1970 +0000
+  summary:     a
+  
+  $ cd ..