strip: report both bundle files in case of exception (issue5368)

If strip fails while recovering the temporary bundle (e.g. because a
hook fails), we tell the user only about the backup bundle, not about
the temporary bundle. Since the user did not ask to strip the commits
in the temporary bundle, that's the more important bundle to mention,
so let's do that (and also mention the backup bundle as usual).

mercurial/repair.py

@@ -230,7 +230,7 b' def strip(ui, repo, nodelist, backup=Tru'
         if backupfile:
             ui.warn(_("strip failed, full bundle stored in '%s'\n")
                     % vfs.join(backupfile))
-        elif chgrpfile:
+        if chgrpfile:
             ui.warn(_("strip failed, partial bundle stored in '%s'\n")
                     % vfs.join(chgrpfile))
         raise

tests/test-strip.t

@@ -367,11 +367,50 b' 2 is parent of 3, only one strip should '
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     a
   
+Failed hook while applying "saveheads" bundle.
+
+  $ hg strip 2 --config hooks.pretxnchangegroup.bad=false
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
+  transaction abort!
+  rollback completed
+  strip failed, full bundle stored in '$TESTTMP/test/.hg/strip-backup/*-backup.hg' (glob)
+  strip failed, partial bundle stored in '$TESTTMP/test/.hg/strip-backup/*-temp.hg' (glob)
+  abort: pretxnchangegroup.bad hook exited with status 1
+  [255]
+  $ restore
+  $ hg log -G
+  o  changeset:   4:443431ffac4f
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     e
+  |
+  o  changeset:   3:65bd5f99a4a3
+  |  parent:      1:ef3a871183d7
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     d
+  |
+  | o  changeset:   2:264128213d29
+  |/   user:        test
+  |    date:        Thu Jan 01 00:00:00 1970 +0000
+  |    summary:     c
+  |
+  @  changeset:   1:ef3a871183d7
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     b
+  |
+  o  changeset:   0:9ab35a2d17cb
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     a
+  
 
 2 different branches: 2 strips
 
   $ hg strip 2 4
-  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
   $ hg log -G
   o  changeset:   2:65bd5f99a4a3