transplant: do not rollback on patching error (issue3379)

Otherwise, all transplanted revisions are gone and the failing one cannot be
fixed (unless it is the first one).

I do not know what is the expected behaviour with rollback, probably something
pull-like. Non-conflicting cases should work as previously. But something like:

  $ hg transplant r1 r2
  commiting r1 as c1
  failing r2
  $ hg transplant --continue
  committing r2 as c2
  $ hg rollback

would reset the repository to its state before the "transplant --continue"
instead of the whole transplant session. To fix this we might need a way to
open an existing journal file, not sure this is worth the pain.

hgext/transplant.py

@@ -20,6 +20,9 b' from mercurial import bundlerepo, hg, me'
 from mercurial import patch, revlog, scmutil, util, error, cmdutil
 from mercurial import revset, templatekw
 
+class TransplantError(error.Abort):
+    pass
+
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 
@@ -171,11 +174,17 b' class transplanter(object):'
                 del revmap[rev]
                 if patchfile or domerge:
                     try:
+                        try:
                         n = self.applyone(repo, node,
                                           source.changelog.read(node),
                                           patchfile, merge=domerge,
                                           log=opts.get('log'),
                                           filter=opts.get('filter'))
+                        except TransplantError:
+                            # Do not rollback, it is up to the user to
+                            # fix the merge or cancel everything
+                            tr.close()
+                            raise
                         if n and domerge:
                             self.ui.status(_('%s merged at %s\n') % (revstr,
                                       short(n)))
@@ -259,7 +268,7 b' class transplanter(object):'
                 p2 = node
                 self.log(user, date, message, p1, p2, merge=merge)
                 self.ui.write(str(inst) + '\n')
-                raise util.Abort(_('fix up the merge and run '
+                raise TransplantError(_('fix up the merge and run '
                                    'hg transplant --continue'))
         else:
             files = None

tests/test-transplant.t

@@ -212,7 +212,9 b' transplant --continue'
   > baz
   > EOF
   $ echo toremove > toremove
+  $ echo baz > baz
   $ hg ci -Amfoo
+  adding baz
   adding foo
   adding toremove
   $ cat <<EOF > foo
@@ -226,17 +228,22 b' transplant --continue'
   adding added
   removing toremove
   $ echo bar > bar
+  $ cat > baz <<EOF
+  > before baz
+  > baz
+  > after baz
+  > EOF
   $ hg ci -Ambar
   adding bar
   $ echo bar2 >> bar
   $ hg ci -mbar2
   $ hg up 0
-  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ echo foobar > foo
   $ hg ci -mfoobar
   created new head
   $ hg transplant 1:3
-  applying a1e30dd1b8e7
+  applying 46ae92138f3c
   patching file foo
   Hunk #1 FAILED at 0
   1 out of 1 hunks FAILED -- saving rejects to file foo.rej
@@ -250,7 +257,7 b" transplant -c shouldn't use an old chang"
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ rm added
   $ hg transplant 1
-  applying a1e30dd1b8e7
+  applying 46ae92138f3c
   patching file foo
   Hunk #1 FAILED at 0
   1 out of 1 hunks FAILED -- saving rejects to file foo.rej
@@ -258,17 +265,41 b" transplant -c shouldn't use an old chang"
   abort: fix up the merge and run hg transplant --continue
   [255]
   $ hg transplant --continue
-  a1e30dd1b8e7 transplanted as f1563cf27039
+  46ae92138f3c transplanted as 9159dada197d
   $ hg transplant 1:3
-  skipping already applied revision 1:a1e30dd1b8e7
-  applying 1739ac5f6139
-  1739ac5f6139 transplanted to d649c221319f
-  applying 0282d5fbbe02
-  0282d5fbbe02 transplanted to 77418277ccb3
+  skipping already applied revision 1:46ae92138f3c
+  applying 9d6d6b5a8275
+  9d6d6b5a8275 transplanted to 2d17a10c922f
+  applying 1dab759070cf
+  1dab759070cf transplanted to e06a69927eb0
   $ hg locate
   added
   bar
+  baz
   foo
+
+test multiple revisions and --continue
+
+  $ hg up -qC 0
+  $ echo bazbaz > baz
+  $ hg ci -Am anotherbaz baz
+  created new head
+  $ hg transplant 1:3
+  applying 46ae92138f3c
+  46ae92138f3c transplanted to 1024233ea0ba
+  applying 9d6d6b5a8275
+  patching file baz
+  Hunk #1 FAILED at 0
+  1 out of 1 hunks FAILED -- saving rejects to file baz.rej
+  patch failed to apply
+  abort: fix up the merge and run hg transplant --continue
+  [255]
+  $ echo fixed > baz
+  $ hg transplant --continue
+  9d6d6b5a8275 transplanted as d80c49962290
+  applying 1dab759070cf
+  1dab759070cf transplanted to aa0ffe6bd5ae
+
   $ cd ..
 
 Issue1111: Test transplant --merge