only update submodule when it is not on a specific branch

diff --git a/autogen.sh b/autogen.sh
index 266a808..27a3ca2 100755 (executable)
--- a/autogen.sh
+++ b/autogen.sh
@@ -11,7 +11,20 @@ then
   echo "+ Setting up common submodule"
   git submodule init
 fi
-git submodule update
+
+# only update if the submodule is tracking master at some version,
+# which means there is no branch name
+cd common
+branch=`git branch | grep ^* | cut -c 3-`
+cd ..
+
+if test "x$branch" == "x(no branch)"
+then
+  echo "+ Updating common submodule"
+  git submodule update common
+else
+  echo "+ Not updating common submodule on branch $branch"
+fi
 
 # source helper functions
 if test ! -f common/gst-autogen.sh;