From 4d5230d1d85a910f04cd2618decc5402023d00ff Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Tue, 26 Feb 2013 22:03:04 +0100
Subject: [PATCH] Only add existing targets to the Qt4 target depends
 properties.

Qt can be configured in ways which disable certain modules. Make
sure we don't fail on that.
---
 Modules/FindQt4.cmake | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Modules/FindQt4.cmake b/Modules/FindQt4.cmake
index 078c03189..f25e12121 100644
--- a/Modules/FindQt4.cmake
+++ b/Modules/FindQt4.cmake
@@ -965,13 +965,17 @@ if (QT_QMAKE_EXECUTABLE AND QTVERSION)
   macro(_qt4_add_target_depends_internal _QT_MODULE _PROPERTY)
     if (TARGET Qt4::${_QT_MODULE})
       foreach(_DEPEND ${ARGN})
-        if (NOT TARGET Qt4::Qt${_DEPEND})
-          message(FATAL_ERROR "_qt4_add_target_depends invoked with invalid arguments")
+        set(_VALID_DEPENDS)
+        if (TARGET Qt4::Qt${_DEPEND})
+          list(APPEND _VALID_DEPENDS Qt4::Qt${_DEPEND})
         endif()
-        set_property(TARGET Qt4::${_QT_MODULE} APPEND PROPERTY
-          ${_PROPERTY}
-          "Qt4::Qt${_DEPEND}"
-        )
+        if (_VALID_DEPENDS)
+          set_property(TARGET Qt4::${_QT_MODULE} APPEND PROPERTY
+            ${_PROPERTY}
+            "${_VALID_DEPENDS}"
+          )
+        endif()
+        set(_VALID_DEPENDS)
       endforeach()
     endif()
   endmacro()