[__git] Add a --no-updates flag to support old static behaviour.

Users relying on this would probably be better off using tags, but this enables
old behaviour with minor changes in existing manifests.

cdist/conf/type/__git/explorer/needs-update

@@ -1,5 +1,10 @@
 #!/bin/sh -e
 
+if [ -f "$__object/parameter/no-updates" ]; then
+    # User requested explicitly not to have updates
+    exit
+fi
+
 destination="/$__object_id"
 
 state_should="$(cat "$__object/parameter/state")"

cdist/conf/type/__git/gencode-remote

@@ -25,6 +25,10 @@ owner_is=$(cat "$__object/explorer/owner")
 group_is=$(cat "$__object/explorer/group")
 needs_update=$(cat "$__object/explorer/needs-update")
 
+if [ -f "$__object/parameter/no-updates" ]; then
+	no_updates="YES"
+fi
+
 state_should=$(cat "$__object/parameter/state")
 
 branch_should=$(cat "$__object/parameter/branch")
@@ -78,7 +82,7 @@ EOF
             echo "su -m '$git_user' -c \"git checkout '$branch_should'\""
             echo "change $branch_is -> $branch_should" >> "$__messages_out"
             repo_changed="YES"
-        elif [ "$needs_update" = "YES" ]; then
+        elif [ -z "$no_updates" ] && [ "$needs_update" = "YES" ]; then
             # The remote has newer information than our repository.
             # Fetch was done in the explorer, here we can just pull
             echo "su -m '$git_user' -c \"git -C '$destination' pull\""

cdist/conf/type/__git/man.rst

@@ -47,6 +47,12 @@ mode-recursive
    If present and --mode is passed, the given permissions will be applied
    recursively to the working directory.
 
+no-updates
+   If present the repository will not be updated after first check out.
+   Notice that this does not affect behaviour if you change the target
+   tag / branch, in which case the type will still ensure the specified one
+   is checked out.
+
 recursive
    Passes the --recurse-submodules flag to git when cloning the repository.
 

cdist/conf/type/__git/parameter/boolean

@@ -1,3 +1,4 @@
 mode-recursive
+no-updates
 recursive
 shallow