Merge branch 'backport-3.16-automoc-path-prefix-off' into release-3.16

Merge-request: !5105

Help/prop_tgt/AUTOMOC_PATH_PREFIX.rst

@@ -13,7 +13,7 @@ the ``-p`` path prefix option.  ``moc`` usually generates a
 relative include path in that case.
 
 :prop_tgt:`AUTOMOC_PATH_PREFIX` is initialized from the variable
-:variable:`CMAKE_AUTOMOC_PATH_PREFIX`, which is ``ON`` by default.
+:variable:`CMAKE_AUTOMOC_PATH_PREFIX`, which is ``OFF`` by default.
 
 See the :manual:`cmake-qt(7)` manual for more information on using CMake
 with Qt.
@@ -24,8 +24,7 @@ Reproducible builds
 For reproducible builds is is recommended to keep headers that are ``moc``
 compiled in one of the target
 :command:`include directories <target_include_directories>` and set
-:prop_tgt:`AUTOMOC_PATH_PREFIX` to ``ON`` (which is the default).  This ensures
-that
+:prop_tgt:`AUTOMOC_PATH_PREFIX` to ``ON``.  This ensures that:
 
 - ``moc`` output files are identical on different build setups,
 - ``moc`` output files will compile correctly when the source and/or

Help/variable/CMAKE_AUTOMOC_PATH_PREFIX.rst

@@ -8,4 +8,4 @@ This variable is used to initialize the :prop_tgt:`AUTOMOC_PATH_PREFIX`
 property on all the targets.  See that target property for additional
 information.
 
-The default value is ``ON``.
+The default value is ``OFF``.

Modules/CMakeGenericSystem.cmake

@@ -26,7 +26,9 @@ set(CMAKE_FIND_LIBRARY_SUFFIXES ".so" ".a")
 
 set(CMAKE_AUTOGEN_ORIGIN_DEPENDS ON)
 set(CMAKE_AUTOMOC_COMPILER_PREDEFINES ON)
-set(CMAKE_AUTOMOC_PATH_PREFIX ON)
+if(NOT DEFINED CMAKE_AUTOMOC_PATH_PREFIX)
+  set(CMAKE_AUTOMOC_PATH_PREFIX OFF)
+endif()
 set(CMAKE_AUTOMOC_MACRO_NAMES "Q_OBJECT" "Q_GADGET" "Q_NAMESPACE")
 
 # basically all general purpose OSs support shared libs

Tests/QtAutogen/MocIncludeSymlink/CMakeLists.txt

@@ -61,6 +61,7 @@ macro(buildMocInclude sourceDir binaryDir)
     "${sourceDir}"
     MocInclude
     CMAKE_FLAGS "-DQT_TEST_VERSION=${QT_TEST_VERSION}"
+                "-DCMAKE_AUTOMOC_PATH_PREFIX=ON"
                 "-DCMAKE_AUTOGEN_VERBOSE=${CMAKE_AUTOGEN_VERBOSE}"
                 "-DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE}"
     OUTPUT_VARIABLE output