[bobthefish] More virtualenv tweaks

 * Inline a one-line method that's called one place
 * Make sure __bobthecow_virtualenv_python_version doesn't fail if python isn't a symlink.
 * Add a visual segment indicator after python version glyph.

themes/bobthefish/fish_prompt.fish

@@ -310,25 +310,27 @@ function __bobthefish_prompt_dir -d 'Display a shortened form of the current dir
 end
 
 function __bobthefish_virtualenv_python_version -d 'Get current python version'
-  switch (readlink (which python))
+  set -l python_version (readlink (which python))
+  switch "$python_version"
     case python2
       echo $__bobthefish_superscript_glyph[2]
     case python3
       echo $__bobthefish_superscript_glyph[3]
     case pypy
       echo $__bobthefish_pypy_glyph
-    end
-end
-
-function __bobthefish_virtualenv -d 'Get the current virtualenv'
-  echo $__bobthefish_virtualenv_glyph(__bobthefish_virtualenv_python_version) (basename "$VIRTUAL_ENV")
+  end
 end
 
 function __bobthefish_prompt_virtualfish -d "Display activated virtual environment (only for virtualfish, virtualenv's activate.fish changes prompt by itself)"
   set -q VIRTUAL_ENV; or return
+  set -l version_glyph (__bobthefish_virtualenv_python_version)
+  if test "$version_glyph"
+    __bobthefish_start_segment $__bobthefish_med_blue $__bobthefish_lt_grey
+    echo -n -s $__bobthefish_virtualenv_glyph $version_glyph
+  end
   __bobthefish_start_segment $__bobthefish_med_blue $__bobthefish_lt_grey
   set_color $__bobthefish_lt_grey --bold
-  echo -n -s (__bobthefish_virtualenv) ' '
+  echo -n -s (basename "$VIRTUAL_ENV") ' '
   set_color normal
 end