Fix check for system NSPR

xpinstall/packager/Makefile.in

@@ -77,7 +77,7 @@ NSPR_DIR	= $(DIST)/bin
 ifndef EXCLUDE_NSPR_LIBS
 NSPR_LDIR	= $(findstring -L,$(NSPR_LIBS))
 ifneq ($(NSPR_LDIR),)
-NSPR_DIR	= $(patsubst %lib,%bin,$(subst -L,,$(word 1,$(NSPR_LIBS))))
+NSPR_DIR	= $(subst -L,,$(word 1,$(NSPR_LIBS)))
 endif
 endif
 
@@ -104,11 +104,14 @@ endif
 
 all export libs install:: $(TARGETS)
 
+_FULL_NSPR_DIR := $(shell cd $(NSPR_DIR); pwd)
+_FULL_DIST_DIR := $(shell cd $(DIST)/bin; pwd)
+
 $(PACKAGE): $(DIST)/bin/mozilla-bin
-ifneq ($(NSPR_DIR),$(DIST)/bin)
-	@chmod 755 $(NSPR_DIR)/*
-	@echo "Copying NSPR..."
-	@cp -p $(NSPR_DIR)/* $(DIST)/bin/.
+ifneq ($(_FULL_NSPR_DIR),$(_FULL_DIST_DIR))
+	@chmod 755 $(NSPR_DIR)/*$(DLL_SUFFIX)
+	@echo "Copying NSPR libs..."
+	@cp -p $(NSPR_DIR)/*$(DLL_SUFFIX) $(DIST)/bin/.
 endif
 	@rm -rf $(DIST)/$(MOZ_PKG_APPNAME) $(DIST)/$(PKG_BASENAME).tar $@ $(EXCLUDE_LIST)
 # NOTE: this must be a cp now that dist links into the tree so that we