# HG changeset patch
# User Siddharth Agarwal <sid0@fb.com>
# Date 1444897150 25200
# Node ID 121f80d14e4be85ef124495742515c2612bc155c
# Parent  e9a0d5f5c225bd5551e4d56471305e5adaabcd71
merge.applyupdates: call driverpreprocess before starting merge actions

We also need to update our internal state to whatever state driverpreprocess
leaves it in.

Adding an error state separate from the unresolved count is too big a
refactoring for now, so we hack around it by setting it to a positive value to
indicate an error state.

diff -r e9a0d5f5c225 -r 121f80d14e4b mercurial/merge.py
--- a/mercurial/merge.py	Thu Oct 15 01:17:29 2015 -0700
+++ b/mercurial/merge.py	Thu Oct 15 01:19:10 2015 -0700
@@ -942,6 +942,27 @@
         util.setflags(repo.wjoin(f), 'l' in flags, 'x' in flags)
         updated += 1
 
+    mergeactions = actions['m']
+    # the ordering is important here -- ms.mergedriver will raise if the merge
+    # driver has changed, and we want to be able to bypass it when overwrite is
+    # True
+    usemergedriver = not overwrite and mergeactions and ms.mergedriver
+
+    if usemergedriver:
+        ms.commit()
+        proceed = driverpreprocess(repo, ms, wctx, labels=labels)
+        # the driver might leave some files unresolved
+        unresolvedf = set(ms.unresolved())
+        if not proceed:
+            # XXX setting unresolved to at least 1 is a hack to make sure we
+            # error out
+            return updated, merged, removed, max(len(unresolvedf), 1)
+        newactions = []
+        for f, args, msg in mergeactions:
+            if f in unresolvedf:
+                newactions.append((f, args, msg))
+        mergeactions = newactions
+
     # premerge
     tocomplete = []
     for f, args, msg in actions['m']: