AutoRevision: Pick the latest tag in branch, not overall

AutoRevision.cmake was using the latest tag created by git, which is
problematic when running two branches in parallel. Always use the latest tag in
the current branch instead.

(cherry picked from commit 6e41925)

cmake/AutoRevision.cmake

@@ -1,3 +1,7 @@
+# SPDX-License-Identifier: GPLv3-or-later
+# SPDX-FileCopyrightText: James Robertson <[email protected]>
+# SPDX-FileCopyrightText: Louis Moureaux <[email protected]>
+
 # This file runs a collection of git commands to help automate the process
 # of generating the build revision. It takes an update to 3 files by hand
 # to do it manually and automates it.
@@ -30,28 +34,10 @@ if (ok)
   endif()
 endif()
 
-if (ok)
-  # Get a temp value of the full commit hash of the latest tag that is active
-  execute_process(
-    COMMAND ${GIT_EXECUTABLE} --git-dir=${CMAKE_SOURCE_DIR}/.git rev-list --tags --max-count=1
-    OUTPUT_VARIABLE hash
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-    RESULT_VARIABLE STATUS
-    ERROR_QUIET)
-
-  if (STATUS EQUAL 0)
-    message(STATUS "Last tag commit hash: ${hash}")
-  else()
-    # Can't use git
-    message(STATUS "Could not find a git tag")
-    set(ok false)
-  endif()
-endif()
-
 if (ok)
   # Use the temp value to get the latest revision tag
   execute_process(
-    COMMAND ${GIT_EXECUTABLE} --git-dir=${CMAKE_SOURCE_DIR}/.git describe --tags ${hash}
+    COMMAND ${GIT_EXECUTABLE} --git-dir=${CMAKE_SOURCE_DIR}/.git describe --tags --abbrev=0
     OUTPUT_VARIABLE FC21_REV_TAG
     OUTPUT_STRIP_TRAILING_WHITESPACE
     RESULT_VARIABLE STATUS