gimp doesn't like filenames with spaces in them, so added sanitize_filename to escape them. Updated gimp.po to reflect the changed line numbers.

contrib/de_DE/LC_MESSAGES/gimp.po

@@ -21,19 +21,19 @@ msgstr ""
 "dngettext:2,3\n"
 "X-Poedit-Basepath: .\n"
 
-#: gimp.lua:179
+#: gimp.lua:189
 #, lua-format
 msgid "Export Image %i/%i"
 msgstr "Exportiere Bild %i/%i"
 
-#: gimp.lua:184
+#: gimp.lua:194
 msgid "GIMP not found"
 msgstr "GIMP nicht gefunden"
 
-#: gimp.lua:198
+#: gimp.lua:209
 msgid "Launching GIMP..."
 msgstr "Starten von GIMP"
 
-#: gimp.lua:243
+#: gimp.lua:254
 msgid "Edit with GIMP"
 msgstr "Bearbeiten mit GIMP"

contrib/gimp.lua

@@ -174,6 +174,16 @@ local function groupIfNotMember(img, new_img)
   end
 end
 
+local function sanitize_filename(filepath)
+  local path = get_path(filepath)
+  local basename = get_basename(filepath)
+  local filetype = get_filetype(filepath)
+
+  local sanitized = string.gsub(basename, " ", "\\ ")
+
+  return path .. sanitized .. "." .. filetype
+end
+
 local function show_status(storage, image, format, filename,
   number, total, high_quality, extra_data)
     dt.print(string.format(_("Export Image %i/%i"), number, total))
@@ -192,6 +202,7 @@ local function gimp_edit(storage, image_table, extra_data) --finalize
   img_list = ""
 
   for _,exp_img in pairs(image_table) do
+    exp_img = sanitize_filename(exp_img)
     img_list = img_list ..exp_img.. " "
   end