merge: document some internal return values.

mercurial/hg.py

@@ -395,7 +395,8 b' def clean(repo, node, show_stats=True):'
     return stats[3] > 0
 
 def merge(repo, node, force=None, remind=True):
-    """branch merge with node, resolving changes"""
+    """Branch merge with node, resolving changes. Return true if any
+    unresolved conflicts."""
     stats = mergemod.update(repo, node, True, force, False)
     _showstats(repo, stats)
     if stats[3]:

mercurial/merge.py

@@ -255,6 +255,9 b' def applyupdates(repo, action, wctx, mct'
     wctx is the working copy context
     mctx is the context to be merged into the working copy
     actx is the context of the common ancestor
+
+    Return a tuple of counts (updated, merged, removed, unresolved) that
+    describes how many files were affected by the update.
     """
 
     updated, merged, removed, unresolved = 0, 0, 0, 0
@@ -462,6 +465,8 b' def update(repo, node, branchmerge, forc'
                  use 'hg update -C' to discard changes)
     3 = abort: uncommitted local changes
     4 = incompatible options (checked in commands.py)
+
+    Return the same tuple as applyupdates().
     """
 
     onode = node