git prompt: Show stagedstate without dirtystate

I have *no idea* why this was coupled, especially since dirtystate can
be expensive, staged state should not be.

share/functions/fish_git_prompt.fish

@@ -247,11 +247,12 @@ function fish_git_prompt --description "Prompt function for Git"
             # This has to be set explicitly.
             if test "$dirty" = true
                 set dirtystate (__fish_git_prompt_dirty)
-                if test -n "$sha"
-                    set stagedstate (__fish_git_prompt_staged)
-                else
-                    set invalidstate 1
-                end
+            end
+
+            if test -n "$sha"
+                set stagedstate (__fish_git_prompt_staged)
+            else
+                set invalidstate 1
             end
 
             if set -q __fish_git_prompt_showstashstate

tests/checks/git.fish

@@ -38,7 +38,7 @@ complete -C'git add '
 git checkout -b newbranch >/dev/null 2>&1
 fish_git_prompt
 echo # the git prompt doesn't print a newline
-#CHECK: (newbranch)
+#CHECK: (newbranch +)
 
 set -g __fish_git_prompt_show_informative_status 1
 fish_git_prompt
@@ -49,10 +49,8 @@ set -e __fish_git_prompt_show_informative_status
 # Confirm the mode changes back
 fish_git_prompt
 echo
-#CHECK: (newbranch)
+#CHECK: (newbranch +)
 
-# (for some reason stagedstate is only shown with showdirtystate?)
-set -g __fish_git_prompt_showdirtystate 1
 git add foo
 fish_git_prompt
 echo