Merge branch 'no-git-version' into release-3.16

Merge-request: !3910

Source/CMakeVersion.cmake

@@ -19,55 +19,57 @@ else()
   set(CMake_VERSION_IS_RELEASE 0)
 endif()
 
-if(EXISTS ${CMake_SOURCE_DIR}/.git)
-  find_package(Git QUIET)
-  if(GIT_FOUND)
-    macro(_git)
-      execute_process(
-        COMMAND ${GIT_EXECUTABLE} ${ARGN}
-        WORKING_DIRECTORY ${CMake_SOURCE_DIR}
-        RESULT_VARIABLE _git_res
-        OUTPUT_VARIABLE _git_out OUTPUT_STRIP_TRAILING_WHITESPACE
-        ERROR_VARIABLE _git_err ERROR_STRIP_TRAILING_WHITESPACE
-        )
-    endmacro()
-  endif()
-endif()
-
-# Try to identify the current development source version.
-if(COMMAND _git)
-  # Get the commit checked out in this work tree.
-  _git(log -n 1 HEAD "--pretty=format:%h %s" --)
-  set(git_info "${_git_out}")
-else()
-  # Get the commit exported by 'git archive'.
+if(NOT CMake_VERSION_NO_GIT)
+  # If this source was exported by 'git archive', use its commit info.
   set(git_info [==[$Format:%h %s$]==])
-endif()
-
-# Extract commit information if available.
-if(git_info MATCHES "^([0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]?[0-9a-f]?)[0-9a-f]* (.*)$")
-  # Have commit information.
-  set(git_hash "${CMAKE_MATCH_1}")
-  set(git_subject "${CMAKE_MATCH_2}")
 
-  # If this is not the exact commit of a release, add dev info.
-  if(NOT "${git_subject}" MATCHES "^[Cc][Mm]ake ${CMake_VERSION}$")
-    set(CMake_VERSION "${CMake_VERSION}-g${git_hash}")
+  # Otherwise, try to identify the current development source version.
+  if(NOT git_info MATCHES "^([0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]?[0-9a-f]?)[0-9a-f]* "
+      AND EXISTS ${CMake_SOURCE_DIR}/.git)
+    find_package(Git QUIET)
+    if(GIT_FOUND)
+      macro(_git)
+        execute_process(
+          COMMAND ${GIT_EXECUTABLE} ${ARGN}
+          WORKING_DIRECTORY ${CMake_SOURCE_DIR}
+          RESULT_VARIABLE _git_res
+          OUTPUT_VARIABLE _git_out OUTPUT_STRIP_TRAILING_WHITESPACE
+          ERROR_VARIABLE _git_err ERROR_STRIP_TRAILING_WHITESPACE
+          )
+      endmacro()
+    endif()
+    if(COMMAND _git)
+      # Get the commit checked out in this work tree.
+      _git(log -n 1 HEAD "--pretty=format:%h %s" --)
+      set(git_info "${_git_out}")
+    endif()
   endif()
 
-  # If this is a work tree, check whether it is dirty.
-  if(COMMAND _git)
-    _git(update-index -q --refresh)
-    _git(diff-index --name-only HEAD --)
-    if(_git_out)
-      set(CMake_VERSION_IS_DIRTY 1)
+  # Extract commit information if available.
+  if(git_info MATCHES "^([0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]?[0-9a-f]?)[0-9a-f]* (.*)$")
+    # Have commit information.
+    set(git_hash "${CMAKE_MATCH_1}")
+    set(git_subject "${CMAKE_MATCH_2}")
+
+    # If this is not the exact commit of a release, add dev info.
+    if(NOT "${git_subject}" MATCHES "^[Cc][Mm]ake ${CMake_VERSION}$")
+      set(CMake_VERSION "${CMake_VERSION}-g${git_hash}")
+    endif()
+
+    # If this is a work tree, check whether it is dirty.
+    if(COMMAND _git)
+      _git(update-index -q --refresh)
+      _git(diff-index --name-only HEAD --)
+      if(_git_out)
+        set(CMake_VERSION_IS_DIRTY 1)
+      endif()
+    endif()
+  else()
+    # No commit information.
+    if(NOT CMake_VERSION_IS_RELEASE)
+      # Generic development version.
+      set(CMake_VERSION "${CMake_VERSION}-git")
     endif()
-  endif()
-else()
-  # No commit information.
-  if(NOT CMake_VERSION_IS_RELEASE)
-    # Generic development version.
-    set(CMake_VERSION "${CMake_VERSION}-git")
   endif()
 endif()