FindPkgConfig: split args if loaded from environment

It's common for some people to use the PKG_CONFIG environment variable
to not only load a custom pkg-config/pkgconf but also to load some
default arguments such as `--static` or `--keep-system-libs` which often
worked since shell scripts would call `$PKG_CONFIG --libs pkg` without
quotes, but this breaks FindPkgConfig since it uses the full string as
`argv[0]` and might try looking for a binary called `pkgconf --static`,
instead of looking for `pkgconf` and adding `--static` as the `argv[1]`

Additionally adds RunCMake.FindPkgConfig ARGN test case

Fixes: #22305
Signed-off-by: Christopher Degawa <ccom@randomderp.com>

4 files changed, 54 insertions, 0 deletions

diff --git a/Tests/RunCMake/FindPkgConfig/FindPkgConfig_GET_MATCHING_ARGN.cmake b/Tests/RunCMake/FindPkgConfig/FindPkgConfig_GET_MATCHING_ARGN.cmake
new file mode 100644
index 0000000..e49ff22
--- /dev/null
+++ b/Tests/RunCMake/FindPkgConfig/FindPkgConfig_GET_MATCHING_ARGN.cmake
@@ -0,0 +1,17 @@
+if(WIN32)
+    set(ENV{PKG_CONFIG} "\"${CMAKE_CURRENT_SOURCE_DIR}\\dummy-pkg-config.bat\" --static --print-errors")
+else()
+    set(ENV{PKG_CONFIG} "\"${CMAKE_CURRENT_SOURCE_DIR}/dummy-pkg-config.sh\" --static --print-errors")
+endif()
+
+find_package(PkgConfig REQUIRED)
+
+if(NOT PKG_CONFIG_ARGN STREQUAL "--static;--print-errors")
+  message(SEND_ERROR "PKG_CONFIG_ARGN has wrong value '${PKG_CONFIG_ARGN}'")
+endif()
+
+_pkgconfig_invoke("none" "prefix" "output" "")
+
+if(NOT prefix_output STREQUAL "Received;--static;Received;--print-errors")
+  message(SEND_ERROR "prefix_output has wrong value '${prefix_output}'")
+endif()
diff --git a/Tests/RunCMake/FindPkgConfig/RunCMakeTest.cmake b/Tests/RunCMake/FindPkgConfig/RunCMakeTest.cmake
index e7f008c..17e046a 100644
--- a/Tests/RunCMake/FindPkgConfig/RunCMakeTest.cmake
+++ b/Tests/RunCMake/FindPkgConfig/RunCMakeTest.cmake
@@ -12,6 +12,7 @@ run_cmake(FindPkgConfig_PKGCONFIG_PATH)
 run_cmake(FindPkgConfig_PKGCONFIG_PATH_NO_CMAKE_PATH)
 run_cmake(FindPkgConfig_PKGCONFIG_PATH_NO_CMAKE_ENVIRONMENT_PATH)
 run_cmake(FindPkgConfig_extract_frameworks)
+run_cmake(FindPkgConfig_GET_MATCHING_ARGN)
 
 if(APPLE)
   run_cmake(FindPkgConfig_extract_frameworks_target)
diff --git a/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.bat b/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.bat
index b038370..c91713b 100755
--- a/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.bat
+++ b/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.bat
@@ -1,5 +1,10 @@
 @ECHO OFF
 
+rem variables to get around `--static --version` printing the received
+rem message and then version
+set static=false
+set print_errors=false
+
 :LOOP
 
 IF "%1"=="" (
@@ -21,7 +26,19 @@ IF "%1"=="--exists" (
     EXIT /B 0
   )
 )
+IF "%1"=="--static" (
+  set static=true
+)
+IF "%1"=="--print-errors" (
+  set print_errors=true
+)
 SHIFT
 IF NOT "%~1"=="" GOTO LOOP
 
+IF "%static%"=="true" ECHO Received --static
+IF "%print_errors%"=="true" ECHO Received --print-errors
+
+IF "%static%"=="true" GOTO :EOF
+IF "%print_errors%"=="true" GOTO :EOF
+
 EXIT /B 255
diff --git a/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.sh b/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.sh
index 56bba30..4021bf7 100755
--- a/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.sh
+++ b/Tests/RunCMake/FindPkgConfig/dummy-pkg-config.sh
@@ -4,6 +4,11 @@
 # to the --exists argument with the PKG_CONFIG_PATH environment variable
 # and returns 1 if they are different.
 
+# variables to get around `--static --version` printing the received
+# message and then version
+static=false
+print_errors=false
+
 while [ $# -gt 0 ]; do
   case $1 in
     --version)
@@ -17,7 +22,21 @@ while [ $# -gt 0 ]; do
       echo "Found:    ${PKG_CONFIG_PATH}"
       [ "${last}" = "${PKG_CONFIG_PATH}" ] && exit 0 || exit 1
       ;;
+    --static)
+      static=true
+      ;;
+    --print-errors)
+      print_errors=true
+      ;;
   esac
   shift
 done
+
+$static && echo "Received --static"
+$print_errors && echo "Received --print-errors"
+
+if $static || $print_errors; then
+  exit 0
+fi
+
 exit 255