# HG changeset patch
# User Anton Shestakov <av6@dwimlabs.net>
# Date 1570433936 -25200
# Node ID a9929dd36405993e35891e0af5e246e38c88b5e1
# Parent  a8fa397795c1dc1768f9023218fc38d3b4cd3e5f
pick: don't create any successors when there were no changes (issue6093)

For example, when a changeset that user is trying to pick was already grafted
or rebased (and no obsmarkers were created), pick will naturally say that
there's no changes to commit and will not create the new commit. In that case
it should not mark any changeset as a successor of the picked changeset,
because the actual file changes were already there before picking.

Technically, pick could (and did before this patch) mark the wdir commit as a
successor of picked changeset (may be useful in the most trivial cases when
e.g. wdir is a graft of the required change), but there are cases when the
picked change is introduced in an ancestor of wdir, or even in multiple
ancestors piece by piece. Pick definitely shouldn't be trying to guess
something this complicated, so with this patch it always marks the picked
change as pruned if it gave no changes to commit.

diff -r a8fa397795c1 -r a9929dd36405 CHANGELOG
--- a/CHANGELOG	Sat Oct 05 14:26:19 2019 -0400
+++ b/CHANGELOG	Mon Oct 07 14:38:56 2019 +0700
@@ -1,6 +1,11 @@
 Changelog
 =========
 
+9.2.2 - in progress
+-------------------
+
+  * pick: don't create any successors when there were no changes (issue6093),
+
 9.2.1 -- 2019-10-05
 -------------------
 
diff -r a8fa397795c1 -r a9929dd36405 hgext3rd/evolve/cmdrewrite.py
--- a/hgext3rd/evolve/cmdrewrite.py	Sat Oct 05 14:26:19 2019 -0400
+++ b/hgext3rd/evolve/cmdrewrite.py	Mon Oct 07 14:38:56 2019 +0700
@@ -1519,8 +1519,11 @@
 
         if pickstate:
             pickstate.delete()
-        newctx = repo[newnode] if newnode else pctx
-        replacements = {origctx.node(): [newctx.node()]}
+        if newnode is None:
+            replacements = {origctx.node(): []}
+        else:
+            newctx = repo[newnode]
+            replacements = {origctx.node(): [newctx.node()]}
         scmutil.cleanupnodes(repo, replacements, operation=b"pick")
 
         if newnode is None:
diff -r a8fa397795c1 -r a9929dd36405 tests/test-pick.t
--- a/tests/test-pick.t	Sat Oct 05 14:26:19 2019 -0400
+++ b/tests/test-pick.t	Mon Oct 07 14:38:56 2019 +0700
@@ -172,6 +172,17 @@
   |
   o  0:1f0dee641bb7 add a
   
+
+there were no changes to commit, so there shouldn't be any predecessors of 6,
+and 2 should say it was pruned (issue6093)
+
+  $ hg olog --all --hidden -r 2+6
+  x  4538525df7e2 (2) add c
+       pruned using pick by test (Thu Jan 01 00:00:00 1970 +0000)
+  
+  @  c4636a81ebeb (6) add c
+  
+
 interrupted pick
 
   $ hg up d46dc301d92f