FindQt4: Clarify the Qt4_FOUND variable

QT4_FOUND variable became deprecated in CMake 2.8.11 where Qt4_FOUND was
introduced.

Modules/FindKDE3.cmake

@@ -212,7 +212,7 @@ if(NOT UNIX AND KDE3_FIND_REQUIRED)
 endif()
 
 # If Qt4 has already been found, fail.
-if(QT4_FOUND)
+if(Qt4_FOUND)
   if(KDE3_FIND_REQUIRED)
     message( FATAL_ERROR "KDE3/Qt3 and Qt4 cannot be used together in one project.")
   else()

Modules/FindQt3.cmake

@@ -92,7 +92,7 @@ cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
 #  QT_WRAP_UI set true if QT_UIC_EXECUTABLE is found
 
 # If Qt4 has already been found, fail.
-if(QT4_FOUND)
+if(Qt4_FOUND)
   if(Qt3_FIND_REQUIRED)
     message( FATAL_ERROR "Qt3 and Qt4 cannot be used together in one project.")
   else()

Modules/FindQt4.cmake

@@ -127,17 +127,18 @@ Result Variables
 This module defines the following variables:
 
 ``Qt4_FOUND``
-  Boolean whether Qt4 has been found.  If false, don't try to use Qt4.
+  Boolean indicating whether (the requested version of) Qt4 is found.
+
 ``QT_FOUND``
-  Boolean whether Qt4 has been found.  If false, don't try to use Qt4.  This
-  variable is for compatibility with other Qt find modules.
-``QT4_FOUND``
-  Boolean whether Qt4 has been found.  If false, don't try to use Qt4.  This
-  variable is for backward compatibility only.
+  Boolean indicating whether (the requested version of) Qt4 has been found.
+  This variable is available for compatibility with other Qt find modules.
+
 ``QT_VERSION_MAJOR``
   The major version of Qt found.
+
 ``QT_VERSION_MINOR``
   The minor version of Qt found.
+
 ``QT_VERSION_PATCH``
   The patch version of Qt found.
 
@@ -438,6 +439,15 @@ such uses:
   the ``QtCore``, ``QtGui`` and ``QtDeclarative`` components on the project
   target ``myexe``.
 
+Deprecated Variables
+^^^^^^^^^^^^^^^^^^^^
+
+The following variables are provided for backward compatibility:
+
+``QT4_FOUND``
+  .. deprecated:: 2.8.11
+    Use ``Qt4_FOUND``, which has the same value.
+
 Examples
 ^^^^^^^^
 

Tests/CMakeLists.txt

@@ -593,11 +593,11 @@ if(BUILD_TESTING)
   if(NOT DEFINED CMake_TEST_Qt4)
     set(CMake_TEST_Qt4 1)
   endif()
-  if(CMake_TEST_Qt4 AND NOT QT4_FOUND)
+  if(CMake_TEST_Qt4 AND NOT Qt4_FOUND)
     find_package(Qt4 QUIET)
   endif()
 
-  if(CMake_TEST_Qt4 AND QT4_FOUND)
+  if(CMake_TEST_Qt4 AND Qt4_FOUND)
     # test whether the Qt4 which has been found works, on some machines
     # which run nightly builds there were errors like "wrong file format"
     # for libQtCore.so. So first check it works, and only if it does add

Tests/CMakeOnly/AllFindModules/CMakeLists.txt

@@ -44,7 +44,7 @@ foreach(FIND_MODULE IN LISTS FIND_MODULES)
 endforeach()
 
 # Qt4 is not present, so we can check Qt3
-if (NOT QT4_FOUND)
+if (NOT Qt4_FOUND)
     set(DESIRED_QT_VERSION 3)
     foreach(FIND_MODULE ${NO_QT4_MODULES} "Qt")
         do_find(${FIND_MODULE})

Tests/RunCMake/CMakeLists.txt

@@ -618,7 +618,7 @@ endif()
 if(NOT CMAKE_GENERATOR MATCHES "Visual Studio")
   add_RunCMake_test(VisibilityPreset)
 endif()
-if (QT4_FOUND)
+if (Qt4_FOUND)
   set(CompatibleInterface_ARGS -DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE})
 endif()
 add_RunCMake_test(CompatibleInterface)
@@ -871,10 +871,10 @@ endif()
 if(CMake_TEST_Qt5)
   find_package(Qt5Core QUIET)
 endif()
-if (CMake_TEST_Qt4 AND CMake_TEST_Qt5 AND QT4_FOUND AND Qt5Core_FOUND AND NOT Qt5Core_VERSION VERSION_LESS 5.1.0)
+if (CMake_TEST_Qt4 AND CMake_TEST_Qt5 AND Qt4_FOUND AND Qt5Core_FOUND AND NOT Qt5Core_VERSION VERSION_LESS 5.1.0)
   add_RunCMake_test(IncompatibleQt)
 endif()
-if (CMake_TEST_Qt4 AND QT4_FOUND)
+if (CMake_TEST_Qt4 AND Qt4_FOUND)
   add_RunCMake_test(ObsoleteQtMacros -DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE})
 endif()