Bug 536173 - Build fails when building platform.ini with an uncommitted merge: "ValueError: too many values to unpack", r=ted

toolkit/xre/Makefile.in

@@ -219,7 +219,7 @@ DEFINES     += -DHAVE_USR_LIB64_DIR
 endif
 endif
 
-MOZ_SOURCE_STAMP ?= $(shell hg -R $(topsrcdir) parent --template="{node|short}\n" 2>/dev/null)
+MOZ_SOURCE_STAMP ?= $(firstword $(shell hg -R $(topsrcdir) parent --template="{node|short}\n" 2>/dev/null))
 # strip a trailing slash from the repo URL because it's not always present,
 # and we want to construct a working URL in buildconfig.html
 # make+shell+sed = awful