Index: contrib/client-side/svnmerge.py
===================================================================
--- contrib/client-side/svnmerge.py	(revision 19182)
+++ contrib/client-side/svnmerge.py	(working copy)
@@ -256,7 +256,13 @@
     # matters: if it's non-empty there is a modification.
     out = launchsvn("status -q %s" % dir)
     if out and out[0].strip():
-        error('"%s" has local modifications; it must be clean' % dir)
+        # Permit multiple 'svnmerge init's (with differing copyfrom
+        # parameter) within a single revision.
+        out = launchsvn("diff %s" % dir)
+        if not (len(out) <= 7 and \
+                out[1].find("Property changes on:") != -1 and \
+                out[3].find("Name: svnmerge-integrated") != -1):
+           error('"%s" has local modifications; it must be clean' % dir)
     for L in launchsvn("status -u %s" % dir):
         if len(L) > 7 and L[7] == '*':
             error('"%s" is not up to date; please "svn update" first' % dir)