am 06898660: A nothing-to-do build should do nothing.

Merge commit '068986605b2afcd5e044b62f22ac6ecd5c15b519' into froyo-plus-aosp

* commit '068986605b2afcd5e044b62f22ac6ecd5c15b519':
  A nothing-to-do build should do nothing.

core/Makefile

@@ -802,8 +802,7 @@ endif
 # -----------------------------------------------------------------
 # host tools needed to build OTA packages
 
-.PHONY: otatools
-otatools: $(HOST_OUT_EXECUTABLES)/minigzip \
+OTATOOLS :=  $(HOST_OUT_EXECUTABLES)/minigzip \
 	  $(HOST_OUT_EXECUTABLES)/mkbootfs \
 	  $(HOST_OUT_EXECUTABLES)/mkbootimg \
 	  $(HOST_OUT_EXECUTABLES)/fs_config \
@@ -815,6 +814,9 @@ otatools: $(HOST_OUT_EXECUTABLES)/minigzip \
 	  $(HOST_OUT_JAVA_LIBRARIES)/dumpkey.jar \
 	  $(HOST_OUT_JAVA_LIBRARIES)/signapk.jar
 
+.PHONY: otatools
+otatools: $(OTATOOLS)
+
 # -----------------------------------------------------------------
 # A zip of the directories that map to the target filesystem.
 # This zip can be used to create an OTA package or filesystem image
@@ -966,7 +968,7 @@ else
 $(INTERNAL_OTA_PACKAGE_TARGET): scriptmode := $(TARGET_OTA_SCRIPT_MODE)
 endif
 
-$(INTERNAL_OTA_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) otatools
+$(INTERNAL_OTA_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(OTATOOLS)
 	@echo "Package OTA: $@"
 	$(hide) ./build/tools/releasetools/ota_from_target_files \
 	   -m $(scriptmode) \
@@ -1100,7 +1102,7 @@ else
 $(INTERNAL_UPDATE_PACKAGE_TARGET): extensions := $(TARGET_RELEASETOOLS_EXTENSIONS)
 endif
 
-$(INTERNAL_UPDATE_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) otatools
+$(INTERNAL_UPDATE_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(OTATOOLS)
 	@echo "Package: $@"
 	$(hide) ./build/tools/releasetools/img_from_target_files \
 	   -s $(extensions) \