From ce9efcf4a901fbb245fc7a9a6605b8c8fc25e91d Mon Sep 17 00:00:00 2001
From: Joerg Bornemann <joerg.bornemann@qt.io>
Date: Mon, 13 Jul 2020 09:22:46 +0200
Subject: [PATCH] CMake: Fix QT_STAGING_PREFIX for repos other than qtbase

For repositories other than qtbase the QT_STAGING_PREFIX was empty,
because it was only determined in qtbase.

Also, we save the CMAKE_STAGING_PREFIX in the Qt6BuildInternals package
and set this variable if it's not explicitly set by the user.
As with CMAKE_INSTALL_PREFIX this behavior can be prevented by defining
QT_BUILD_INTERNALS_NO_FORCE_SET_STAGING_PREFIX=ON.

Change-Id: I73100abbef24f5d3fb8f82029d0374176edc8048
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
---
 cmake/QtBuild.cmake       |  6 ++++++
 cmake/QtPostProcess.cmake | 12 ++++++++++++
 cmake/QtSetup.cmake       |  2 --
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/cmake/QtBuild.cmake b/cmake/QtBuild.cmake
index 404415a99f..7ad7e6e252 100644
--- a/cmake/QtBuild.cmake
+++ b/cmake/QtBuild.cmake
@@ -125,6 +125,12 @@ qt_configure_process_path(INSTALL_DESCRIPTIONSDIR
                          "${INSTALL_DATADIR}/modules"
                           "Module description files directory")
 
+if(CMAKE_CROSSCOMPILING AND NOT "${CMAKE_STAGING_PREFIX}" STREQUAL "")
+    set(QT_STAGING_PREFIX "${CMAKE_STAGING_PREFIX}")
+else()
+    set(QT_STAGING_PREFIX "${CMAKE_INSTALL_PREFIX}")
+endif()
+
 function(qt_internal_set_up_global_paths)
     # Compute the values of QT_BUILD_DIR, QT_INSTALL_DIR, QT_CONFIG_BUILD_DIR, QT_CONFIG_INSTALL_DIR
     # taking into account whether the current build is a prefix build or a non-prefix build,
diff --git a/cmake/QtPostProcess.cmake b/cmake/QtPostProcess.cmake
index 73d9d2dcd6..b6cbe57d41 100644
--- a/cmake/QtPostProcess.cmake
+++ b/cmake/QtPostProcess.cmake
@@ -459,6 +459,18 @@ endif()\n")
                    "set(OPENSSL_ROOT_DIR \"${openssl_root_cmake_path}\" CACHE STRING \"\")\n")
         endif()
 
+        if(NOT "${CMAKE_STAGING_PREFIX}" STREQUAL "")
+            string(APPEND QT_EXTRA_BUILD_INTERNALS_VARS
+                "
+# If no explicit CMAKE_STAGING_PREFIX is provided, force set the original Qt staging prefix,
+if(\"$\{CMAKE_STAGING_PREFIX}\" STREQUAL \"\"
+   AND NOT QT_BUILD_INTERNALS_NO_FORCE_SET_STAGING_PREFIX)
+    set(CMAKE_STAGING_PREFIX \"${CMAKE_STAGING_PREFIX}\" CACHE PATH
+        \"Staging path prefix, prepended onto install directories on the host machine.\" FORCE)
+endif()
+")
+        endif()
+
         qt_generate_install_prefixes(install_prefix_content)
 
         string(APPEND QT_EXTRA_BUILD_INTERNALS_VARS "${install_prefix_content}")
diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
index 16b334fac1..ede764b542 100644
--- a/cmake/QtSetup.cmake
+++ b/cmake/QtSetup.cmake
@@ -87,8 +87,6 @@ if (PROJECT_NAME STREQUAL "QtBase" AND NOT QT_BUILD_STANDALONE_TESTS)
     else()
         set(__qt_will_install_value ON)
     endif()
-    set(QT_STAGING_PREFIX "${__qt_prefix}" CACHE INTERNAL
-        "Install prefix on the build machine. Either CMAKE_INSTALL_PREFIX or CMAKE_STAGING_PREFIX.")
     set(QT_WILL_INSTALL ${__qt_will_install_value} CACHE BOOL
         "Boolean indicating if doing a Qt prefix build (vs non-prefix build)." FORCE)
     unset(__qt_prefix)