Allow KeePassXC version overrides from file in addition to Git tags

.gitignore

@@ -10,3 +10,4 @@ release*/
 *.swp
 
 .DS_Store
+.version

CMakeLists.txt

@@ -80,19 +80,22 @@ set_property(CACHE KEEPASSXC_BUILD_TYPE PROPERTY STRINGS Snapshot Release PreRel
 execute_process(COMMAND git tag --points-at HEAD
         WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
         OUTPUT_VARIABLE GIT_TAG)
-if(GIT_TAG)
-  string(REGEX REPLACE "\r?\n$" "" GIT_TAG "${GIT_TAG}")
+if(NOT GIT_TAG AND EXISTS ${CMAKE_SOURCE_DIR}/.version)
+  file(READ ${CMAKE_SOURCE_DIR}/.version OVERRIDE_VERSION)
+endif()
 
-  if(GIT_TAG MATCHES "^[\\.0-9]+-(alpha|beta)[0-9]+$")
+string(REGEX REPLACE "(\r?\n)+" "" OVERRIDE_VERSION "${OVERRIDE_VERSION}")
+if(OVERRIDE_VERSION)
+  if(OVERRIDE_VERSION MATCHES "^[\\.0-9]+-(alpha|beta)[0-9]+$")
     set(KEEPASSXC_BUILD_TYPE PreRelease)
-    set(KEEPASSXC_VERSION ${GIT_TAG})
-  elseif(GIT_TAG MATCHES "^[\\.0-9]+$")
+    set(KEEPASSXC_VERSION ${OVERRIDE_VERSION})
+  elseif(OVERRIDE_VERSION MATCHES "^[\\.0-9]+$")
     set(KEEPASSXC_BUILD_TYPE Release)
-    set(KEEPASSXC_VERSION ${GIT_TAG})
+    set(KEEPASSXC_VERSION ${OVERRIDE_VERSION})
   endif()
 endif()
 
-if(KEEPASSXC_BUILD_TYPE STREQUAL "PreRelease" AND NOT GIT_TAG)
+if(KEEPASSXC_BUILD_TYPE STREQUAL "PreRelease" AND NOT OVERRIDE_VERSION)
   set(KEEPASSXC_VERSION "${KEEPASSXC_VERSION}-preview")
 elseif(KEEPASSXC_BUILD_TYPE STREQUAL "Snapshot")
   set(KEEPASSXC_VERSION "${KEEPASSXC_VERSION}-snapshot")