rebase: add :abort merge tool

Summary: This adds a merge tool to only rebase if there aren't conflicts, which I think will be widely useful. It's for IMM only at the moment.

Reviewed By: DurhamG, quark-zju

Differential Revision: D8493065

fbshipit-source-id: 32ccc0e53af27d275a56bcac80861a421d7abfc6

hgext/rebase.py

@@ -1022,6 +1022,12 @@ def rebase(ui, repo, templ=None, **opts):
             )
             rbsrt.inmemory = False
             return _origrebase(ui, repo, rbsrt, **opts)
+        except error.AbortMergeToolError as e:
+            ui.status(_("%s; exiting.\n") % e)
+            clearstatus(repo)
+            mergemod.mergestate.clean(repo)
+            if repo.currenttransaction():
+                repo.currenttransaction().abort()
     else:
         return _origrebase(ui, repo, rbsrt, **opts)
 

mercurial/error.py

@@ -409,3 +409,7 @@ class InMemoryMergeConflictsError(Exception):
     """Exception raised when merge conflicts arose during an in-memory merge."""
 
     __bytes__ = _tobytes
+
+
+class AbortMergeToolError(Abort):
+    """User specified :abort and there was a merge conflict; abort the merge."""

mercurial/filemerge.py

@@ -247,6 +247,18 @@ def _matcheol(file, back):
                 util.writefile(file, newdata)
 
 
+@internaltool("abort", nomerge)
+def _iabort(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
+    if fcd.changectx().isinmemory():
+        raise error.AbortMergeToolError(
+            _("hit merge conflicts, and --tool :abort passed")
+        )
+    else:
+        # Support coming soon; it's tricker to do without IMM and has to be
+        # implemented per-command.
+        raise error.Abort(_("--tool :abort only works with in-memory merge"))
+
+
 @internaltool("prompt", nomerge)
 def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Asks the user which of the local `p1()` or the other `p2()` version to
@@ -258,7 +270,7 @@ def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     # conflicts.
     if fcd.changectx().isinmemory():
         raise error.InMemoryMergeConflictsError(
-            "in-memory merge does not " "support file conflicts"
+            "in-memory merge does not support file conflicts"
         )
 
     prompts = partextras(labels)

tests/test-rebase-inmemory-abort-tool.t

@@ -0,0 +1,53 @@
+Tests the :abort merge tool
+
+  $ newrepo
+  $ enable rebase fbamend morestatus
+  $ setconfig morestatus.show=True
+  $ setconfig rebase.singletransaction=True
+  $ setconfig rebase.experimental.inmemory=True
+  $ setconfig rebase.experimental.inmemory.nomergedriver=False
+  $ setconfig rebase.experimental.inmemory.canrebaseworkingcopy=True
+  $ setconfig rebase.experimental.inmemory.newconflictswitching=True
+  $ setconfig rebase.experimental.inmemorywarning="rebasing in-memory!"
+
+  $ hg debugdrawdag <<'EOS'
+  > c
+  > |
+  > b g
+  > |/
+  > a
+  > EOS
+  $ hg up -q g
+  $ echo "conflict" > c
+  $ hg add -q
+  $ hg amend -q
+  $ hg up c
+  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ echo "local change" > b
+  $ hg rebase -r tip -d . --tool :abort
+  rebasing in-memory!
+  rebasing 3:955ac081fc7c "g" (tip)
+  hit merge conflicts, and --tool :abort passed; exiting.
+  $ hg st
+  M b
+  $ cat b
+  local change
+
+A rebase without a conflict behaves the same:
+  $ hg rebase -r tip -d .~1 --tool :abort
+  rebasing in-memory!
+  rebasing 3:955ac081fc7c "g" (tip)
+  saved backup bundle to $TESTTMP/repo1/.hg/strip-backup/955ac081fc7c-77e57574-rebase.hg
+
+It fails without IMM:
+
+  $ setconfig rebase.experimental.inmemory=False
+  $ hg up -C .
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ hg st
+  $ hg rebase -r tip -d . --tool :abort
+  rebasing 3:20b9638feb86 "g" (tip)
+  transaction abort!
+  rollback completed
+  abort: --tool :abort only works with in-memory merge
+  [255]