Merge branch 'jokester/override--ignore-submodules' (#2214)

Closes #2214

lib/git.zsh

@@ -17,6 +17,16 @@ function parse_git_dirty() {
     if [[ "$DISABLE_UNTRACKED_FILES_DIRTY" == "true" ]]; then
       FLAGS+='--untracked-files=no'
     fi
+    case "$GIT_STATUS_IGNORE_SUBMODULES" in
+      git)
+        # let git decide (this respects per-repo config in .gitmodules)
+        ;;
+      *)
+        # if unset: ignore dirty submodules
+        # other values are passed to --ignore-submodules
+        FLAGS+="--ignore-submodules=${GIT_STATUS_IGNORE_SUBMODULES:-dirty}"
+        ;;
+    esac
     STATUS=$(command git status ${FLAGS} 2> /dev/null | tail -n1)
   fi
   if [[ -n $STATUS ]]; then