[recipes] Handle mixed units on the shopping list

[Matthias Clasen <matthiasc src gnome org>]

commit b890fab4e792bb69ffe867639de52fd7557ac813
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Mar 1 02:24:05 2018 -0500

    Handle mixed units on the shopping list
    
    This should not happen in real life, but I ran into this
    situation in a demo, and it crashed the app.

 src/gr-shopping-page.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/src/gr-shopping-page.c b/src/gr-shopping-page.c
index fb50832..0c06651 100644
--- a/src/gr-shopping-page.c
+++ b/src/gr-shopping-page.c
@@ -240,10 +240,15 @@ ingredient_format_unit (Ingredient *ing)
                         a1 += a;
                 }
                 else {
-                        g_error ("conversion yielded different units...why...");
+                        if (s->len > 0)
+                          g_string_append (s, ", ");
+                        gr_convert_format (s, a, u);
+                        g_warning ("conversion yielded different units (%s: %s vs %s)...why...", 
ing->ingredient, gr_unit_get_name (u), gr_unit_get_name (u1));
                 }
         }
 
+        if (s->len > 0)
+          g_string_append (s, ", ");
         gr_convert_format (s, a1, u1);
 
         return g_strdup (s->str);