--- a/b2g/app/Makefile.in
+++ b/b2g/app/Makefile.in
@@ -24,32 +24,37 @@ APP_NAME = $(MOZ_APP_DISPLAYNAME)
 APP_VERSION = $(MOZ_APP_VERSION)
 
 ifdef MOZ_DEBUG
 APP_NAME := $(APP_NAME)Debug
 endif
 
 AB_CD = $(MOZ_UI_LOCALE)
 
-AB := $(firstword $(subst -, ,$(AB_CD)))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+else
+LPROJ_ROOT := $(firstword $(subst -, ,$(AB_CD)))
+endif
+LPROJ := Contents/Resources/$(LPROJ_ROOT).lproj
 
 clean clobber repackage::
 	rm -rf $(DIST)/$(APP_NAME).app
 
 libs-preqs = \
   $(call mkdir_deps,$(DIST)/$(APP_NAME).app/Contents/MacOS) \
-  $(call mkdir_deps,$(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj) \
+  $(call mkdir_deps,$(DIST)/$(APP_NAME).app/$(LPROJ)) \
   $(NULL)
 
 .PHONY: repackage
 tools repackage:: $(libs-preqs)
 	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents $(DIST)/$(APP_NAME).app --exclude English.lproj
-	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj
+	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(DIST)/$(APP_NAME).app/$(LPROJ)
 	sed -e 's/%MOZ_APP_VERSION%/$(MOZ_APP_VERSION)/' -e 's/%MOZ_APP_NAME%/$(MOZ_APP_NAME)/' -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' -e 's/%APP_BINARY%/$(APP_BINARY)/' $(srcdir)/macbuild/Contents/Info.plist.in > $(DIST)/$(APP_NAME).app/Contents/Info.plist
-	sed -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(DIST)/$(APP_NAME).app/Contents/Resources/$(AB).lproj/InfoPlist.strings
+	sed -e 's/%APP_VERSION%/$(APP_VERSION)/' -e 's/%APP_NAME%/$(APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(DIST)/$(APP_NAME).app/$(LPROJ_ROOT)/InfoPlist.strings
 	rsync -a --exclude 'mangle' --exclude 'shlibsign' --exclude-from='$(srcdir)/macbuild/Contents/MacOS-files.in' $(DIST)/bin/ $(DIST)/$(APP_NAME).app/Contents/Resources
 	rsync -a --include-from='$(srcdir)/macbuild/Contents/MacOS-files.in' --exclude '*' $(DIST)/bin/ $(DIST)/$(APP_NAME).app/Contents/MacOS
 ifdef LIBXUL_SDK
 	cp $(LIBXUL_DIST)/bin/xulrunner$(BIN_SUFFIX) $(DIST)/$(APP_NAME).app/Contents/MacOS/$(APP_BINARY)
 	rsync -a --exclude nsinstall --copy-unsafe-links $(LIBXUL_DIST)/XUL.framework $(DIST)/$(APP_NAME).app/Contents/Frameworks
 else
 	$(RM) $(DIST)/$(APP_NAME).app/Contents/MacOS/$(PROGRAM)
 	rsync -aL $(PROGRAM) $(DIST)/$(APP_NAME).app/Contents/MacOS

--- a/browser/app/Makefile.in
+++ b/browser/app/Makefile.in
@@ -74,31 +74,36 @@ ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
 MAC_APP_NAME = $(MOZ_APP_DISPLAYNAME)
 
 ifdef MOZ_DEBUG
 MAC_APP_NAME := $(MAC_APP_NAME)Debug
 endif
 
 AB_CD = $(MOZ_UI_LOCALE)
 
-AB := $(firstword $(subst -, ,$(AB_CD)))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+else
+LPROJ_ROOT := $(firstword $(subst -, ,$(AB_CD)))
+endif
+LPROJ := Contents/Resources/$(LPROJ_ROOT).lproj
 
 clean clobber repackage::
 	$(RM) -r $(dist_dest)
 
 MAC_BUNDLE_VERSION = $(shell $(PYTHON) $(srcdir)/macversion.py --version=$(MOZ_APP_VERSION) --buildid=$(DEPTH)/config/buildid)
 
 .PHONY: repackage
 tools repackage:: $(PROGRAM)
 	$(MKDIR) -p $(dist_dest)/Contents/MacOS
-	$(MKDIR) -p $(dist_dest)/Contents/Resources/$(AB).lproj
+	$(MKDIR) -p $(dist_dest)/$(LPROJ)
 	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents $(dist_dest) --exclude English.lproj
-	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(dist_dest)/Contents/Resources/$(AB).lproj
+	rsync -a --exclude '*.in' $(srcdir)/macbuild/Contents/Resources/English.lproj/ $(dist_dest)/$(LPROJ)
 	sed -e 's/%APP_VERSION%/$(MOZ_APP_VERSION)/' -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' -e 's/%MOZ_MACBUNDLE_ID%/$(MOZ_MACBUNDLE_ID)/' -e 's/%MAC_BUNDLE_VERSION%/$(MAC_BUNDLE_VERSION)/' $(srcdir)/macbuild/Contents/Info.plist.in > $(dist_dest)/Contents/Info.plist
-	sed -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(dist_dest)/Contents/Resources/$(AB).lproj/InfoPlist.strings
+	sed -e 's/%MAC_APP_NAME%/$(MAC_APP_NAME)/' $(srcdir)/macbuild/Contents/Resources/English.lproj/InfoPlist.strings.in | iconv -f UTF-8 -t UTF-16 > $(dist_dest)/$(LPROJ)/InfoPlist.strings
 	rsync -a --exclude-from='$(srcdir)/macbuild/Contents/MacOS-files.in' $(DIST)/bin/ $(dist_dest)/Contents/Resources
 	rsync -a --include-from='$(srcdir)/macbuild/Contents/MacOS-files.in' --exclude '*' $(DIST)/bin/ $(dist_dest)/Contents/MacOS
 	$(RM) $(dist_dest)/Contents/MacOS/$(PROGRAM)
 	rsync -aL $(PROGRAM) $(dist_dest)/Contents/MacOS
 	cp -RL $(DIST)/branding/firefox.icns $(dist_dest)/Contents/Resources/firefox.icns
 	cp -RL $(DIST)/branding/document.icns $(dist_dest)/Contents/Resources/document.icns
 	printf APPLMOZB > $(dist_dest)/Contents/PkgInfo
 endif

--- a/browser/installer/Makefile.in
+++ b/browser/installer/Makefile.in
@@ -121,18 +121,23 @@ DEFINES += -DBINPATH=$(BINPATH)
 
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
 RESPATH = $(_APPNAME)/Contents/Resources
 else
 RESPATH = $(BINPATH)
 endif
 DEFINES += -DRESPATH=$(RESPATH)
 
-AB = $(firstword $(subst -, ,$(AB_CD)))
-DEFINES += -DAB=$(AB)
+LPROJ_ROOT = $(firstword $(subst -, ,$(AB_CD)))
+ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+endif
+endif
+DEFINES += -DLPROJ_ROOT=$(LPROJ_ROOT)
 
 DEFINES += -DMOZ_ICU_VERSION=$(MOZ_ICU_VERSION)
 ifdef MOZ_NATIVE_ICU
 DEFINES += -DMOZ_NATIVE_ICU
 endif
 ifdef MOZ_SHARED_ICU
 DEFINES += -DMOZ_SHARED_ICU
 endif

--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -33,17 +33,17 @@
 #filter substitution
 
 #ifdef XP_MACOSX
 ; Mac bundle stuff
 @APPNAME@/Contents/Info.plist
 @APPNAME@/Contents/PkgInfo
 @RESPATH@/firefox.icns
 @RESPATH@/document.icns
-@RESPATH@/@AB@.lproj/*
+@RESPATH@/@LPROJ_ROOT@.lproj/*
 #endif
 
 [@AB_CD@]
 @RESPATH@/browser/chrome/@AB_CD@@JAREXT@
 @RESPATH@/browser/chrome/@AB_CD@.manifest
 @RESPATH@/chrome/@AB_CD@@JAREXT@
 @RESPATH@/chrome/@AB_CD@.manifest
 @RESPATH@/browser/defaults/profile/bookmarks.html

--- a/toolkit/locales/l10n.mk
+++ b/toolkit/locales/l10n.mk
@@ -27,17 +27,22 @@
 #   MOZ_APP_VERSION and MOZ_LANGPACK_EID.
 
 
 run_for_effects := $(shell if test ! -d $(DIST); then $(NSINSTALL) -D $(DIST); fi)
 
 # This makefile uses variable overrides from the libs-% target to
 # build non-default locales to non-default dist/ locations. Be aware!
 
-AB = $(firstword $(subst -, ,$(AB_CD)))
+LPROJ_ROOT = $(firstword $(subst -, ,$(AB_CD)))
+ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
+ifeq (zh-TW,$(AB_CD))
+LPROJ_ROOT := $(subst -,_,$(AB_CD))
+endif
+endif
 
 # These are defaulted to be compatible with the files the wget-en-US target
 # pulls. You may override them if you provide your own files. You _must_
 # override them when MOZ_PKG_PRETTYNAMES is defined - the defaults will not
 # work in that case.
 ZIP_IN ?= $(_ABS_DIST)/$(PACKAGE)
 WIN32_INSTALLER_IN ?= $(_ABS_DIST)/$(PKG_INST_PATH)$(PKG_INST_BASENAME).exe
 
@@ -111,18 +116,18 @@ repackage-zip:  libs-$(AB_CD)
 ifdef MOZ_STUB_INSTALLER
 	$(STUB_HOOK)
 endif
 	$(PYTHON) $(MOZILLA_DIR)/toolkit/mozapps/installer/l10n-repack.py $(STAGEDIST) $(DIST)/xpi-stage/locale-$(AB_CD) \
 		$(MOZ_PKG_EXTRAL10N) \
 		$(if $(filter omni,$(MOZ_PACKAGER_FORMAT)),$(if $(NON_OMNIJAR_FILES),--non-resource $(NON_OMNIJAR_FILES)))
 
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
-ifneq (en,$(AB))
-	mv $(STAGEDIST)/en.lproj $(STAGEDIST)/$(AB).lproj
+ifneq (en,$(LPROJ_ROOT))
+	mv $(STAGEDIST)/en.lproj $(STAGEDIST)/$(LPROJ_ROOT).lproj
 endif
 ifdef MOZ_CRASHREPORTER
 # On Mac OS X, the crashreporter.ini file needs to be moved from under the
 # application bundle's Resources directory where all other l10n files are
 # located to the crash reporter bundle's Resources directory.
 	mv $(STAGEDIST)/crashreporter.app/Contents/Resources/crashreporter.ini \
 	  $(STAGEDIST)/../MacOS/crashreporter.app/Contents/Resources/crashreporter.ini
 	$(RM) -rf $(STAGEDIST)/crashreporter.app
@@ -133,19 +138,19 @@ endif
 	cd $(DIST)/l10n-stage; \
 	  $(MAKE_PACKAGE)
 ifdef MAKE_COMPLETE_MAR
 	$(MAKE) -C $(MOZDEPTH)/tools/update-packaging full-update AB_CD=$(AB_CD) \
 	  MOZ_PKG_PRETTYNAMES=$(MOZ_PKG_PRETTYNAMES) \
 	  PACKAGE_BASE_DIR='$(_ABS_DIST)/l10n-stage'
 endif
 # packaging done, undo l10n stuff
-ifneq (en,$(AB))
+ifneq (en,$(LPROJ_ROOT))
 ifeq (cocoa,$(MOZ_WIDGET_TOOLKIT))
-	mv $(STAGEDIST)/$(AB).lproj $(STAGEDIST)/en.lproj
+	mv $(STAGEDIST)/$(LPROJ_ROOT).lproj $(STAGEDIST)/en.lproj
 endif
 endif
 	$(NSINSTALL) -D $(DIST)/$(PKG_PATH)
 	mv -f '$(DIST)/l10n-stage/$(PACKAGE)' '$(ZIP_OUT)'
 	if test -f '$(DIST)/l10n-stage/$(PACKAGE).asc'; then mv -f '$(DIST)/l10n-stage/$(PACKAGE).asc' '$(ZIP_OUT).asc'; fi
 
 repackage-zip-%: $(STAGEDIST)
 	@$(MAKE) repackage-zip AB_CD=$* ZIP_IN='$(ZIP_IN)'