From 79410eeb1f32974aaf1e95aef439a4709fafbc8e Mon Sep 17 00:00:00 2001
From: Ilya Kulakov <kulakov.ilya@gmail.com>
Date: Tue, 26 Apr 2016 18:50:38 -0400
Subject: [PATCH] ExternalProject: Initialize Git submodules recursively and on
 update (#16083)

---
 Help/release/dev/ExternalProject-git-recursive-init.rst | 7 +++++++
 Modules/ExternalProject.cmake                           | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)
 create mode 100644 Help/release/dev/ExternalProject-git-recursive-init.rst

diff --git a/Help/release/dev/ExternalProject-git-recursive-init.rst b/Help/release/dev/ExternalProject-git-recursive-init.rst
new file mode 100644
index 000000000..1ebcced7f
--- /dev/null
+++ b/Help/release/dev/ExternalProject-git-recursive-init.rst
@@ -0,0 +1,7 @@
+ExternalProject-git-recursive-init
+----------------------------------
+
+* The :module:`ExternalProject` module learned to initialize Git submodules
+  recursively and also to initialize new submodules on updates.  Use the
+  ``GIT_SUBMODULES`` option to restrict which submodules are initalized and
+  updated.
diff --git a/Modules/ExternalProject.cmake b/Modules/ExternalProject.cmake
index 9cc8a20a2..7dad6e525 100644
--- a/Modules/ExternalProject.cmake
+++ b/Modules/ExternalProject.cmake
@@ -587,7 +587,7 @@ if(error_code)
 endif()
 
 execute_process(
-  COMMAND \"${git_EXECUTABLE}\" \${git_options} submodule update --recursive ${git_submodules}
+  COMMAND \"${git_EXECUTABLE}\" \${git_options} submodule update --recursive --init ${git_submodules}
   WORKING_DIRECTORY \"${work_dir}/${src_name}\"
   RESULT_VARIABLE error_code
   )
@@ -833,7 +833,7 @@ if(error_code OR is_remote_ref OR NOT (\"\${tag_sha}\" STREQUAL \"\${head_sha}\"
   endif()
 
   execute_process(
-    COMMAND \"${git_EXECUTABLE}\" submodule update --recursive ${git_submodules}
+    COMMAND \"${git_EXECUTABLE}\" submodule update --recursive --init ${git_submodules}
     WORKING_DIRECTORY \"${work_dir}/${src_name}\"
     RESULT_VARIABLE error_code
     )