ENH: Similar to how qmake does it...

      Don't add compile flags for dependent modules the user didn't specify.
      But still add the link libs.  This reduces the number of
      unecessary compile flags.

Modules/UseQt4.cmake

@@ -36,7 +36,7 @@ IF (QT_USE_QT3SUPPORT)
   ADD_DEFINITIONS(-DQT3_SUPPORT)
 ENDIF (QT_USE_QT3SUPPORT)
 
-# list dependent modules, so their modules are automatically on
+# list dependent modules, so dependent libraries are added
 SET(QT_QT3SUPPORT_MODULE_DEPENDS QTGUI QTSQL QTXML QTNETWORK QTCORE)
 SET(QT_QTSVG_MODULE_DEPENDS QTGUI QTXML QTCORE)
 SET(QT_QTUITOOLS_MODULE_DEPENDS QTGUI QTXML QTCORE)
@@ -50,7 +50,7 @@ FOREACH(module QT3SUPPORT QTOPENGL QTASSISTANT QTDESIGNER QTMOTIF QTNSPLUGIN
                QTSCRIPT QTSVG QTUITOOLS QTHELP QTWEBKIT PHONON QTGUI QTTEST 
                QTDBUS QTXML QTSQL QTXMLPATTERNS QTNETWORK QTCORE)
 
-  IF (QT_USE_${module})
+  IF (QT_USE_${module} OR QT_USE_${module}_DEPENDS)
     IF (QT_${module}_FOUND)
       IF(QT_USE_${module})
         STRING(REPLACE "QT" "" qt_module_def "${module}")
@@ -59,12 +59,12 @@ FOREACH(module QT3SUPPORT QTOPENGL QTASSISTANT QTDESIGNER QTMOTIF QTNSPLUGIN
       ENDIF(QT_USE_${module})
       SET(QT_LIBRARIES ${QT_LIBRARIES} ${QT_${module}_LIBRARY} ${QT_${module}_LIB_DEPENDENCIES})
       FOREACH(depend_module ${QT_${module}_MODULE_DEPENDS})
-        SET(QT_USE_${depend_module} 1)
+        SET(QT_USE_${depend_module}_DEPENDS 1)
       ENDFOREACH(depend_module ${QT_${module}_MODULE_DEPENDS})
     ELSE (QT_${module}_FOUND)
       MESSAGE("Qt ${module} library not found.")
     ENDIF (QT_${module}_FOUND)
-  ENDIF (QT_USE_${module})
+  ENDIF (QT_USE_${module} OR QT_USE_${module}_DEPENDS)
   
 ENDFOREACH(module)