# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Date 1490340036 -3600
# Node ID 9e30934d4487b16fd58e98fec4dbbd38aab2a6ad
# Parent  37fa3d83f29422a5de613fc65bba6b4da2dc7a01
stablerange: rearrange the reusing logic to prepare to merge

We'll soon be able to reuse some lower range when dealing with merge too. So we
prepare the code for this in advance for clarity.

diff --git a/hgext3rd/evolve/stablerange.py b/hgext3rd/evolve/stablerange.py
--- a/hgext3rd/evolve/stablerange.py
+++ b/hgext3rd/evolve/stablerange.py
@@ -391,25 +391,24 @@
         p1, p2 = self._parents(rangeid[0], repo.changelog.parentrevs)
         if p2 != nodemod.nullrev:
             return self._slicesrangeatmerge(repo, rangeid, globalindex)
-        assert p1 != nodemod.nullrev
-        rangedepth = self.depthrev(repo, rangeid[0])
-        topsize = rangedepth - globalindex
+
+        reuserev = p1
 
-        parentrange = (p1, rangeid[1])
+        assert reuserev != nodemod.nullrev
+
+        reuserange = (reuserev, rangeid[1])
+        top = (rangeid[0], globalindex)
 
-        if topsize == 1:
-            top = (rangeid[0], globalindex)
-            return [parentrange, top]
-        else:
-            # This will not initiate a recursion since we took appropriate
-            # precaution in the caller of this method to ensure it will be so.
-            # It the parent is a merge that will not be the case but computing
-            # subranges from a merge will not recurse.
-            parentsubranges = self.subranges(repo, parentrange)
-            slices = parentsubranges[:-1] # pop the top
-            top = (rangeid[0], globalindex)
-            slices.append(top)
-            return slices
+        if rangeid[1] + self.rangelength(repo, reuserange) == globalindex:
+            return [reuserange, top]
+        # This will not initiate a recursion since we took appropriate
+        # precaution in the caller of this method to ensure it will be so.
+        # It the parent is a merge that will not be the case but computing
+        # subranges from a merge will not recurse.
+        reusesubranges = self.subranges(repo, reuserange)
+        slices = reusesubranges[:-1] # pop the top
+        slices.append(top)
+        return slices
 
     def _slicesrangeatmerge(self, repo, rangeid, globalindex):
         localindex = globalindex - rangeid[1]