rebase: replace --tool :abort with rebase --noconflict

Summary:
I was thinking about what we need to enable automatic restacking on non-conflicting amends (see the next diff), but I realized the --tool :abort tool I implemented in D8493065 doesn't really work well for this for three reasons:

- It can't handle the case of mergedriver having to run, which is the other reason we'd have to break out of IMM.
- It hard-codes the merge tool. The user might want to specify another tool that doesn't recreate conflicts or solves them differently.
- It'd force callers to detect if IMM will be used (to prevent an on-disk merge hapening by mistake). A flag can implement this much more easily.
- As I learned when writing D8493065, it would require hardcoded logic in every command anyway to support the non-IMM case. (Just raising an abort will leave most commands with an interrupted state.)

So, I think we should replace it with this flag to make auto-restacking work very reliably (we could add it to graft, too). If there was some big demand for --tool :abort we could always add it back in the future.

Reviewed By: quark-zju

Differential Revision: D8701897

fbshipit-source-id: ea3b92d0a224a8ce43edb120b53bec241d92a61d

hgext/rebase.py

@@ -543,7 +543,11 @@ class rebaseruntime(object):
                     else:
                         kindstr = _("artifact rebuild required")
 
-                    if cmdutil.uncommittedchanges(repo):
+                    if self.opts["noconflict"]:
+                        raise error.AbortMergeToolError(
+                            "%s (in %s) and --noconflict passed" % (kindstr, pathstr)
+                        )
+                    elif cmdutil.uncommittedchanges(repo):
                         raise error.UncommitedChangesAbort(
                             _(
                                 "must use on-disk merge for this rebase (%s in %s), but you have working copy changes"
@@ -814,6 +818,12 @@ class rebaseruntime(object):
         ("t", "tool", "", _("specify merge tool")),
         ("c", "continue", False, _("continue an interrupted rebase")),
         ("a", "abort", False, _("abort an interrupted rebase")),
+        (
+            "",
+            "noconflict",
+            False,
+            _("cancel the rebase if there are conflicts (EXPERIMENTAL)"),
+        ),
     ]
     + cmdutil.formatteropts,
     _("[-s REV | -b REV] [-d REV] [OPTION]"),
@@ -966,6 +976,9 @@ def rebase(ui, repo, templ=None, **opts):
             )
             inmemory = False
 
+    if opts.get("noconflict") and not inmemory:
+        raise error.Abort("--noconflict requires in-memory merge")
+
     opts = pycompat.byteskwargs(opts)
     rbsrt = rebaseruntime(repo, ui, templ, inmemory, opts)
 

mercurial/filemerge.py

@@ -247,22 +247,6 @@ def _matcheol(file, back):
                 util.writefile(file, newdata)
 
 
-@internaltool("abort", fullmerge)
-def _iabort(repo, mynode, orig, fcd, *args, **kwargs):
-    if not fcd.changectx().isinmemory():
-        # 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"))
-
-    res = _imerge(repo, mynode, orig, fcd, *args, **kwargs)
-    if res:
-        raise error.AbortMergeToolError(
-            _("hit merge conflicts, and --tool :abort passed")
-        )
-    else:
-        return res
-
-
 @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

tests/test-rebase-inmemory-noconflict.t

@@ -1,4 +1,4 @@
-Tests the :abort merge tool
+Tests the --noconflict rebase flag
 
   $ enable rebase fbamend morestatus
   $ setconfig morestatus.show=True
@@ -24,18 +24,18 @@ Tests the :abort merge tool
 
 
 Confirm it fails when rebasing a change that conflicts:
-  $ hg rebase -r tip -d . --tool :abort
+  $ hg rebase -r tip -d . --noconflict
   rebasing in-memory!
   rebasing 3:955ac081fc7c "g" (tip)
   merging c
-  hit merge conflicts, and --tool :abort passed; exiting.
+  hit merge conflicts (in c) and --noconflict passed; exiting.
   $ hg st
   M b
   $ cat b
   local change
 
 Confirm rebase without a merge behaves the same:
-  $ hg rebase -r tip -d .~1 --tool :abort
+  $ hg rebase -r tip -d .~1 --noconflict
   rebasing in-memory!
   rebasing 3:955ac081fc7c "g" (tip)
   saved backup bundle to $TESTTMP/repo1/.hg/strip-backup/955ac081fc7c-77e57574-rebase.hg
@@ -46,12 +46,8 @@ Confirm the flag fails without IMM:
   $ 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)
-  merging c
-  transaction abort!
-  rollback completed
-  abort: --tool :abort only works with in-memory merge
+  $ hg rebase -r tip -d . --noconflict
+  abort: --noconflict requires in-memory merge
   [255]
 
 Confirm that it rebases a three-way merge, but no conflict:
@@ -71,7 +67,7 @@ Confirm that it rebases a three-way merge, but no conflict:
   o  0 base
   
   $ hg up -qC 0
-  $ hg rebase -r 1 -d 2 --tool :abort
+  $ hg rebase -r 1 -d 2 --noconflict
   rebasing in-memory!
   rebasing 1:12cba56c6d27 "extend to 10"
   merging a