From b92858a5beba687478e56850269bc89bc61b3954 Mon Sep 17 00:00:00 2001
From: Matthieu Rogez <matthieu.rogez@fivesgroup.com>
Date: Fri, 24 Mar 2023 14:18:59 +0100
Subject: [PATCH] cmake: fix directory separators in generated
 packageConfig.cmake files

On windows, meson would mix posix and windows dir separators in the
computed PACKAGE_RELATIVE_PATH.

Here we force posix directory separator even on Windows. This matches
the CMake behavior and fixes interpretation of the resulting path.

Fixes #6955
Fixes #9702
---
 mesonbuild/modules/cmake.py                   |  3 ++-
 .../cmakePackagePrefixDirConfig.cmake.in      |  1 +
 .../26 cmake package prefix dir/meson.build   | 19 +++++++++++++++++++
 .../26 cmake package prefix dir/test.json     |  5 +++++
 4 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 test cases/cmake/26 cmake package prefix dir/cmakePackagePrefixDirConfig.cmake.in
 create mode 100644 test cases/cmake/26 cmake package prefix dir/meson.build
 create mode 100644 test cases/cmake/26 cmake package prefix dir/test.json

diff --git a/mesonbuild/modules/cmake.py b/mesonbuild/modules/cmake.py
index d37c832ab..c6048f925 100644
--- a/mesonbuild/modules/cmake.py
+++ b/mesonbuild/modules/cmake.py
@@ -391,7 +391,8 @@ class CmakeModule(ExtensionModule):
         if not os.path.isabs(abs_install_dir):
             abs_install_dir = os.path.join(prefix, install_dir)
 
-        PACKAGE_RELATIVE_PATH = os.path.relpath(prefix, abs_install_dir)
+        # path used in cmake scripts are POSIX even on Windows
+        PACKAGE_RELATIVE_PATH = pathlib.PurePath(os.path.relpath(prefix, abs_install_dir)).as_posix()
         extra = ''
         if re.match('^(/usr)?/lib(64)?/.+', abs_install_dir):
             extra = PACKAGE_INIT_EXT.replace('@absInstallDir@', abs_install_dir)
diff --git a/test cases/cmake/26 cmake package prefix dir/cmakePackagePrefixDirConfig.cmake.in b/test cases/cmake/26 cmake package prefix dir/cmakePackagePrefixDirConfig.cmake.in
new file mode 100644
index 000000000..a18cb7d4b
--- /dev/null
+++ b/test cases/cmake/26 cmake package prefix dir/cmakePackagePrefixDirConfig.cmake.in	
@@ -0,0 +1 @@
+@PACKAGE_INIT@
diff --git a/test cases/cmake/26 cmake package prefix dir/meson.build b/test cases/cmake/26 cmake package prefix dir/meson.build
new file mode 100644
index 000000000..851371b4b
--- /dev/null
+++ b/test cases/cmake/26 cmake package prefix dir/meson.build	
@@ -0,0 +1,19 @@
+project('cmakePackagePrefixDir', 'c', version: '1.0.0')
+
+cmake = import('cmake')
+
+cmake.configure_package_config_file(
+    name: 'cmakePackagePrefixDir',
+    input: 'cmakePackagePrefixDirConfig.cmake.in',
+    configuration: configuration_data(),
+)
+
+# NOTE: can't use fs.read because cmakePackagePrefixDirConfig.cmake is in build_dir
+python = find_program('python3')
+lines = run_command(python, '-c',
+    '[print(line, end="") for line in open("@0@")]'.format(meson.current_build_dir() / 'cmakePackagePrefixDirConfig.cmake'), check : true,
+).stdout().split('\n')
+
+message(lines)
+
+assert(lines[5] == 'get_filename_component(PACKAGE_PREFIX_DIR "${CMAKE_CURRENT_LIST_DIR}/../../.." ABSOLUTE)')
diff --git a/test cases/cmake/26 cmake package prefix dir/test.json b/test cases/cmake/26 cmake package prefix dir/test.json
new file mode 100644
index 000000000..d6a95051c
--- /dev/null
+++ b/test cases/cmake/26 cmake package prefix dir/test.json	
@@ -0,0 +1,5 @@
+{
+  "installed": [
+    {"type": "file", "file": "usr/lib/cmake/cmakePackagePrefixDir/cmakePackagePrefixDirConfig.cmake"}
+  ]
+}