Merge pull request #993 from UV-CDAT/fix-git-update

Fix git clone & update helper scripts

Author: aashish24

CMake/cdat_modules_extra/git_clone.sh.in

@@ -1,4 +1,10 @@
 #!/bin/sh
 
-cd @CMAKE_INSTALL_PREFIX@
-"@GIT_EXECUTABLE@" clone --depth 1 -b @BRANCH@ @GIT_URL@ @GIT_TARGET@
+cd "@CMAKE_INSTALL_PREFIX@"
+"@GIT_EXECUTABLE@" clone --no-checkout --depth 1 -b @BRANCH@ @GIT_URL@ "@GIT_TARGET@"
+cd "@GIT_TARGET@"
+if [ "$("@GIT_EXECUTABLE@" cat-file -t @BRANCH@)" = tag ]; then
+    "@GIT_EXECUTABLE@" checkout @BRANCH@
+else
+    "@GIT_EXECUTABLE@" checkout origin/@BRANCH@
+fi

CMake/cdat_modules_extra/git_update.sh.in

@@ -1,9 +1,8 @@
 #!/bin/sh
-cd @SOURCE_DIR@
-git fetch origin --prune
-branch_name=$(git symbolic-ref HEAD | sed -e 's,.*\/\(.*\),\1,')
-if [ $? = 0 -a "${branch_name}" != "@BRANCH@" ]; then
-  git checkout -f @BRANCH@
+cd "@SOURCE_DIR@"
+"@GIT_EXECUTABLE@" fetch origin --prune
+if [ "$("@GIT_EXECUTABLE@" cat-file -t @BRANCH@)" = tag ]; then
+    "@GIT_EXECUTABLE@" checkout -f @BRANCH@
+else
+    "@GIT_EXECUTABLE@" checkout -f origin/@BRANCH@
 fi
-git reset --hard origin/@BRANCH@
-