From 248dbfa4a2c8aaed4093b8bf02595972a9f289aa Mon Sep 17 00:00:00 2001
From: baldurk <baldurk@baldurk.org>
Date: Fri, 10 Mar 2017 13:17:46 +0000
Subject: [PATCH] Allow external overriding of auto-fetched git hash identifier
 in cmake

* This is useful if the build doesn't happen within a git checkout and
  you want to pass in the hash anyway, but it also allows adding
  suffixes like -official etc.
---
 CMakeLists.txt | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bfcd19704..b6eb9c5cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,6 +29,8 @@ if(CMAKE_BINARY_DIR STREQUAL CMAKE_SOURCE_DIR)
     message(FATAL_ERROR "In-source builds not allowed")
 endif()
 
+set(BUILD_VERSION_HASH "" CACHE STRING "The current git commit hash, possibly with suffixes to indicate build type")
+
 function(get_git_hash _git_hash)
   if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
     execute_process(
@@ -41,6 +43,9 @@ function(get_git_hash _git_hash)
   if(NOT GIT_HASH)
     set(GIT_HASH "NO_GIT_COMMIT_HASH_DEFINED")
   endif()
+  if(BUILD_VERSION_HASH)
+    set(GIT_HASH "${BUILD_VERSION_HASH}")
+  endif()
   set(${_git_hash} "${GIT_HASH}" PARENT_SCOPE)
 endfunction(get_git_hash)