# HG changeset patch
# User Laurent Charignon <lcharignon@fb.com>
# Date 1435190063 25200
# Node ID 5c385b8125006471ae807c3edb328fdb42cbf58f
# Parent  a433948ca8d29d5bc518fe58b77cee25e756125b
evolve: dedupe divergents when running evolve --all --any or evolve --rev

Before this patch, when running evolve --all --any or evolve --rev with the
--divergent flag, we were selecting all of the divergents. After solving the
first one, its counterparts would get pruned and potentially hidden which would
crash when trying to resolve them. This patch introduces logic to dedupe the
divergents to be resolved by keeping only one per group of divergent with the
lower revision number.

diff --git a/hgext/evolve.py b/hgext/evolve.py
--- a/hgext/evolve.py
+++ b/hgext/evolve.py
@@ -1415,6 +1415,24 @@
                 rdependencies[succ].add(r)
     return dependencies, rdependencies
 
+def _dedupedivergents(repo, revs):
+    """Dedupe the divergents revs in revs to get one from each group with the
+    lowest revision numbers
+    """
+    repo = repo.unfiltered()
+    res = set()
+    # To not reevaluate divergents of the same group once one is encountered
+    discarded = set()
+    for rev in revs:
+        if rev in discarded:
+            continue
+        divergent = repo[rev]
+        base, others = divergentdata(divergent)
+        othersrevs = [o.rev() for o in others]
+        res.add(min([divergent.rev()] + othersrevs))
+        discarded.update(othersrevs)
+    return res
+
 def _selectrevs(repo, allopt, revopt, anyopt, targetcat):
     """select troubles in repo matching according to given options"""
     revs = set()
@@ -1424,6 +1442,9 @@
             revs = scmutil.revrange(repo, revopt) & revs
         elif not anyopt and targetcat == 'unstable':
             revs = set(_aspiringdescendant(repo, repo.revs('(.::) - obsolete()::')))
+        if targetcat == 'divergent':
+            # Pick one divergent per group of divergents
+            revs = _dedupedivergents(repo, revs)
     elif anyopt:
         revs = repo.revs('first(%s())' % (targetcat))
     elif targetcat == 'unstable':
diff --git a/tests/test-divergent.t b/tests/test-divergent.t
new file mode 100644
--- /dev/null
+++ b/tests/test-divergent.t
@@ -0,0 +1,70 @@
+Tests the resolution of divergence
+
+  $ cat >> $HGRCPATH <<EOF
+  > [defaults]
+  > amend=-d "0 0"
+  > fold=-d "0 0"
+  > [web]
+  > push_ssl = false
+  > allow_push = *
+  > [phases]
+  > publish = False
+  > [diff]
+  > git = 1
+  > unified = 0
+  > [ui]
+  > logtemplate = {rev}:{node|short}@{branch}({phase}) {desc|firstline} [{troubles}]\n
+  > [extensions]
+  > hgext.graphlog=
+  > EOF
+  $ echo "evolve=$(echo $(dirname $TESTDIR))/hgext/evolve.py" >> $HGRCPATH
+  $ mkcommit() {
+  >    echo "$1" > "$1"
+  >    hg add "$1"
+  >    hg ci -m "add $1"
+  > }
+
+  $ mkcommits() {
+  >   for i in $@; do mkcommit $i ; done
+  > }
+
+Basic test of divergence: two divergent changesets with the same parents
+With --all --any we dedupe the divergent and solve the divergence once
+
+  $ hg init test1
+  $ cd test1
+  $ mkcommits _a _b
+  $ hg up "desc(_a)"
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ mkcommit bdivergent1
+  created new head
+  $ hg up "desc(_a)"
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ mkcommit bdivergent2
+  created new head
+  $ hg prune -s "desc(bdivergent1)" "desc(_b)"
+  1 changesets pruned
+  $ hg prune -s "desc(bdivergent2)" "desc(_b)" --hidden
+  1 changesets pruned
+  2 new divergent changesets
+  $ hg log -G
+  @  3:e708fd28d5cf@default(draft) add bdivergent2 [divergent]
+  |
+  | o  2:c2f698071cba@default(draft) add bdivergent1 [divergent]
+  |/
+  o  0:135f39f4bd78@default(draft) add _a []
+  
+  $ hg evolve --all --any --divergent
+  merge:[2] add bdivergent1
+  with: [3] add bdivergent2
+  base: [1] add _b
+  updating to "local" conflict
+  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  working directory is now at c26f1d3baed2
+  $ hg log -G
+  @  5:c26f1d3baed2@default(draft) add bdivergent1 []
+  |
+  o  0:135f39f4bd78@default(draft) add _a []
+  
+  $ cd ..