From 165f09d7e7e70ed044c2503027ca2694ccded82a Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Mon, 7 Oct 2019 14:20:45 -0500
Subject: [PATCH] cmake/modules/GetGitRevisionDescription: update to work with
 git-worktree

Found this here: https://phabricator.kde.org/D9172

Signed-off-by: Sage Weil <sage@redhat.com>
---
 cmake/modules/GetGitRevisionDescription.cmake | 14 ++++++----
 .../GetGitRevisionDescription.cmake.in        | 27 ++++++++++++-------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/cmake/modules/GetGitRevisionDescription.cmake b/cmake/modules/GetGitRevisionDescription.cmake
index 85eae1562fe..40a42015a7d 100644
--- a/cmake/modules/GetGitRevisionDescription.cmake
+++ b/cmake/modules/GetGitRevisionDescription.cmake
@@ -53,12 +53,16 @@ function(get_git_head_revision _refspecvar _hashvar)
 		endif()
 		set(GIT_DIR "${GIT_PARENT_DIR}/.git")
 	endwhile()
-	# check if this is a submodule
+	# check if this is a submodule or git-worktree
 	if(NOT IS_DIRECTORY ${GIT_DIR})
-		file(READ ${GIT_DIR} submodule)
-		string(REGEX REPLACE "gitdir: (.*)\n$" "\\1" GIT_DIR_RELATIVE ${submodule})
-		get_filename_component(SUBMODULE_DIR ${GIT_DIR} PATH)
-		get_filename_component(GIT_DIR ${SUBMODULE_DIR}/${GIT_DIR_RELATIVE} ABSOLUTE)
+		file(READ ${GIT_DIR} gitdirfile)
+		string(REGEX REPLACE "gitdir: (.*)\n$" "\\1" GIT_DIR_PATH ${gitdirfile})
+		if(IS_ABSOLUTE ${GIT_DIR_PATH})
+			get_filename_component(GIT_DIR ${GIT_DIR_PATH} ABSOLUTE)
+		else()
+			get_filename_component(LINKED_DIR ${GIT_DIR} PATH)
+			get_filename_component(GIT_DIR ${LINKED_DIR}/${GIT_DIR_PATH} ABSOLUTE)
+		endif()
 	endif()
 	set(GIT_DATA "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/git-data")
 	if(NOT EXISTS "${GIT_DATA}")
diff --git a/cmake/modules/GetGitRevisionDescription.cmake.in b/cmake/modules/GetGitRevisionDescription.cmake.in
index 6d8b708efe5..41cf7ed5fa9 100644
--- a/cmake/modules/GetGitRevisionDescription.cmake.in
+++ b/cmake/modules/GetGitRevisionDescription.cmake.in
@@ -18,21 +18,30 @@ set(HEAD_HASH)
 file(READ "@HEAD_FILE@" HEAD_CONTENTS LIMIT 1024)
 
 string(STRIP "${HEAD_CONTENTS}" HEAD_CONTENTS)
+set(GIT_DIR "@GIT_DIR@")
+# handle git-worktree
+if(EXISTS "${GIT_DIR}/commondir")
+	file(READ "${GIT_DIR}/commondir" GIT_DIR_NEW LIMIT 1024)
+	string(STRIP "${GIT_DIR_NEW}" GIT_DIR_NEW)
+	if(NOT IS_ABSOLUTE "${GIT_DIR_NEW}")
+		get_filename_component(GIT_DIR_NEW ${GIT_DIR}/${GIT_DIR_NEW} ABSOLUTE)
+	endif()
+	if(EXISTS "${GIT_DIR_NEW}")
+		set(GIT_DIR "${GIT_DIR_NEW}")
+	endif()
+endif()
 if(HEAD_CONTENTS MATCHES "ref")
 	# named branch
 	string(REPLACE "ref: " "" HEAD_REF "${HEAD_CONTENTS}")
-	if(EXISTS "@GIT_DIR@/${HEAD_REF}")
-		configure_file("@GIT_DIR@/${HEAD_REF}" "@GIT_DATA@/head-ref" COPYONLY)
-	else()
-		configure_file("@GIT_DIR@/packed-refs" "@GIT_DATA@/packed-refs" COPYONLY)
-		file(READ "@GIT_DATA@/packed-refs" PACKED_REFS)
-		if(${PACKED_REFS} MATCHES "([0-9a-z]*) ${HEAD_REF}")
-			set(HEAD_HASH "${CMAKE_MATCH_1}")
-		endif()
+	if(EXISTS "${GIT_DIR}/${HEAD_REF}")
+		configure_file("${GIT_DIR}/${HEAD_REF}" "@GIT_DATA@/head-ref" COPYONLY)
+	elseif(EXISTS "${GIT_DIR}/logs/${HEAD_REF}")
+		configure_file("${GIT_DIR}/logs/${HEAD_REF}" "@GIT_DATA@/head-ref" COPYONLY)
+		set(HEAD_HASH "${HEAD_REF}")
 	endif()
 else()
 	# detached HEAD
-	configure_file("@GIT_DIR@/HEAD" "@GIT_DATA@/head-ref" COPYONLY)
+	configure_file("${GIT_DIR}/HEAD" "@GIT_DATA@/head-ref" COPYONLY)
 endif()
 
 if(NOT HEAD_HASH)
-- 
2.39.5