[CMake] Always patch the builtins starting from the pristine sources

ExternalProject re-runs the patch step not only after a new download, but
also when the patch command changes, and then on the already patched tree.
Since 0db7792 changed the unuran patch command, this breaks the
incremental opensuse CI build. The configure-time checks of the other
builtins with patches fail the other way around: after a new download, they
skip the patches.

Add ROOT_BUILTIN_PATCH_COMMAND, whose patch step commits the pristine
sources to a git repository in the source directory and resets to them
before applying the patches, so it can always run. Trees patched by the old
commands are handled by undoing their patches first, or, if that fails, by
downloading the sources again. Use it for all builtins with patches.

🤖 Done with the help of AI

Author: guitargeek

builtins/cfitsio/CMakeLists.txt

@@ -27,12 +27,10 @@ if(WIN32)
   set(patch_args --ignore-whitespace)
 endif()
 
-if(NOT EXISTS "${CFITSIO_PREFIX}/src/BUILTIN_CFITSIO/._patched")
-  set(CFITSIO_PATCH_COMMAND PATCH_COMMAND git init COMMAND git apply ${patch_args}
-                ${CMAKE_CURRENT_SOURCE_DIR}/cfitsio-no-find-zlib.diff
-                ${CMAKE_CURRENT_SOURCE_DIR}/no-fortran-wrapper.diff
-                ${CMAKE_CURRENT_SOURCE_DIR}/cfitsio-marker.diff)
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(CFITSIO_PATCH_COMMAND
+                           PATCHES ${CMAKE_CURRENT_SOURCE_DIR}/cfitsio-no-find-zlib.diff
+                                   ${CMAKE_CURRENT_SOURCE_DIR}/no-fortran-wrapper.diff
+                           GIT_APPLY_ARGS ${patch_args})
 
 ExternalProject_Add(
   BUILTIN_CFITSIO

builtins/cfitsio/cfitsio-marker.diff

@@ -11,20 +11,14 @@ set(ROOT_CIVETWEB_VERSION 1.16) # with some patches, so almost 1.17
 set(ROOT_CIVETWEB_PREFIX ${CMAKE_BINARY_DIR}/builtins/CIVETWEB-prefix)
 set(ROOT_CIVETWEB_LIBRARY ${ROOT_CIVETWEB_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}civetweb${CMAKE_STATIC_LIBRARY_SUFFIX})
 
-if (NOT DEFINED GIT_EXECUTABLE)
-  set(GIT_EXECUTABLE "git")
-endif()
 if(WIN32)
   set(GIT_PATCH_ARGS "--ignore-space-change")
 endif()
-# check if the patch has already been applied
-if(NOT EXISTS "${ROOT_CIVETWEB_PREFIX}/src/BUILTIN_CIVETWEB/._patched")
-  set(ROOT_CIVETWEB_PATCH_COMMAND PATCH_COMMAND ${GIT_EXECUTABLE} init COMMAND ${GIT_EXECUTABLE} apply ${GIT_PATCH_ARGS}
-         ${CMAKE_CURRENT_SOURCE_DIR}/1385.patch # https://github.com/civetweb/civetweb/pull/1385
-         ${CMAKE_CURRENT_SOURCE_DIR}/1389.patch # https://github.com/civetweb/civetweb/pull/1389
-         ${CMAKE_CURRENT_SOURCE_DIR}/1423.patch # https://github.com/civetweb/civetweb/pull/1423 for OpenSSL4 compatibility
-         ${CMAKE_CURRENT_SOURCE_DIR}/civetweb-marker.diff)
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(ROOT_CIVETWEB_PATCH_COMMAND
+  PATCHES ${CMAKE_CURRENT_SOURCE_DIR}/1385.patch # https://github.com/civetweb/civetweb/pull/1385
+          ${CMAKE_CURRENT_SOURCE_DIR}/1389.patch # https://github.com/civetweb/civetweb/pull/1389
+          ${CMAKE_CURRENT_SOURCE_DIR}/1423.patch # https://github.com/civetweb/civetweb/pull/1423 for OpenSSL4 compatibility
+  GIT_APPLY_ARGS ${GIT_PATCH_ARGS})
 
 include(ExternalProject)
 

builtins/civetweb/CMakeLists.txt

@@ -23,17 +23,9 @@ set(ROOT_FTGL_PATCH_FILE_3 "${CMAKE_CURRENT_SOURCE_DIR}/0003-fix-nullptr.patch")
 set(ROOT_FTGL_PREFIX ${CMAKE_BINARY_DIR}/builtins/FTGL-prefix)
 set(ROOT_FTGL_LIBRARY ${ROOT_FTGL_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}ftgl${ROOT_FTGL_POSTFIX}${CMAKE_STATIC_LIBRARY_SUFFIX})
 
-if (NOT DEFINED GIT_EXECUTABLE)
-  set(GIT_EXECUTABLE "git")
-endif()
-
-if(NOT EXISTS "${ROOT_FTGL_PREFIX}/src/BUILTIN_FTGL/._patched")
-  set(ROOT_FTGL_PATCH_COMMAND PATCH_COMMAND ${GIT_EXECUTABLE} init COMMAND ${GIT_EXECUTABLE} apply --ignore-space-change --ignore-whitespace
-                ${ROOT_FTGL_PATCH_FILE_1}
-                ${ROOT_FTGL_PATCH_FILE_2}
-                ${ROOT_FTGL_PATCH_FILE_3}
-                ${CMAKE_CURRENT_SOURCE_DIR}/ftgl-marker.diff)
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(ROOT_FTGL_PATCH_COMMAND
+                           PATCHES ${ROOT_FTGL_PATCH_FILE_1} ${ROOT_FTGL_PATCH_FILE_2} ${ROOT_FTGL_PATCH_FILE_3}
+                           GIT_APPLY_ARGS --ignore-space-change --ignore-whitespace)
 
 include(ExternalProject)
 

builtins/civetweb/civetweb-marker.diff

@@ -10,7 +10,7 @@ set(ROOT_GL2PS_VERSION 1.4.2)
 set(ROOT_GL2PS_HASH "8d1c00c1018f96b4b97655482e57dcb0ce42ae2f1d349cd6d4191e7848d9ffe9")
 # Backport fix for static Win32 having being overwritten by shared lib: https://gitlab.onelab.info/gl2ps/gl2ps/-/work_items/30
 # We use all seven commits between 1.4.2 and before bump to 1.4.3
-set(ROOT_GL2PS_PATCH_FILES ${CMAKE_CURRENT_SOURCE_DIR}/v142_post_tag_fixes.patch ${CMAKE_CURRENT_SOURCE_DIR}/gl2ps-marker.patch)
+set(ROOT_GL2PS_PATCH_FILES ${CMAKE_CURRENT_SOURCE_DIR}/v142_post_tag_fixes.patch)
 
 set(ROOT_GL2PS_PREFIX ${CMAKE_BINARY_DIR}/builtins/GL2PS-prefix)
 
@@ -29,10 +29,7 @@ if(WIN32)
   set(patch_args --ignore-whitespace)
 endif()
 
-# check if the patch has already been applied
-if(NOT EXISTS "${ROOT_GL2PS_PREFIX}/src/BUILTIN_GL2PS/._patched")
-  set(GL2PS_PATCH_COMMAND PATCH_COMMAND git init COMMAND git apply ${patch_args} ${ROOT_GL2PS_PATCH_FILES})
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(GL2PS_PATCH_COMMAND PATCHES ${ROOT_GL2PS_PATCH_FILES} GIT_APPLY_ARGS ${patch_args})
 
 ExternalProject_Add(
   BUILTIN_GL2PS

builtins/ftgl/CMakeLists.txt

@@ -28,10 +28,7 @@ if(WIN32)
   set(patch_args --ignore-whitespace)
 endif()
 
-# check if the patch has already been applied
-if(NOT EXISTS "${ROOT_LIBGIF_PREFIX}/src/BUILTIN_LIBGIF/CMakeLists.txt")
-  set(LIBGIF_PATCH_COMMAND PATCH_COMMAND git init COMMAND git apply ${patch_args} ${ROOT_LIBGIF_PATCH_FILE})
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(LIBGIF_PATCH_COMMAND PATCHES ${ROOT_LIBGIF_PATCH_FILE} GIT_APPLY_ARGS ${patch_args})
 
 ExternalProject_Add(
     BUILTIN_LIBGIF

builtins/ftgl/ftgl-marker.diff

@@ -11,9 +11,8 @@ set(ROOT_UNURAN_HASH "098793854c590b4c2c7e98bc48a45408875f48c5ad47650b5fabbd3e94
 set(ROOT_UNURAN_PREFIX ${CMAKE_BINARY_DIR}/builtins/UNURAN-prefix)
 set(ROOT_UNURAN_LIBRARY ${ROOT_UNURAN_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}unuran${CMAKE_STATIC_LIBRARY_SUFFIX})
 set(ROOT_UNURAN_PATCH_FILE_1 "${CMAKE_CURRENT_SOURCE_DIR}/0001-allow-compilation-from-CMake.patch")
-if (NOT DEFINED GIT_EXECUTABLE)
-  set(GIT_EXECUTABLE "git")
-endif()
+ROOT_BUILTIN_PATCH_COMMAND(ROOT_UNURAN_PATCH_COMMAND PATCHES ${ROOT_UNURAN_PATCH_FILE_1}
+                           GIT_APPLY_ARGS --ignore-space-change --ignore-whitespace)
 
 include(ExternalProject)
 
@@ -39,8 +38,7 @@ ExternalProject_Add(
   URL ${lcgpackages}/unuran-${ROOT_UNURAN_VERSION}.tar.gz
       https://statmath.wu.ac.at/unuran/unuran-${ROOT_UNURAN_VERSION}.tar.gz
   URL_HASH SHA256=${ROOT_UNURAN_HASH}
-  PATCH_COMMAND ${GIT_EXECUTABLE} init -q
-        COMMAND ${GIT_EXECUTABLE} apply --ignore-space-change --ignore-whitespace ${ROOT_UNURAN_PATCH_FILE_1}
+  ${ROOT_UNURAN_PATCH_COMMAND}
   SOURCE_SUBDIR src
   LOG_DOWNLOAD  TRUE
 # The following three are disabled to avoid CI failure in Ubuntu22 that has outdated CMake version