Fix a couple minor issues noticed by tests.

lib/lyx2lyx/lyx_2_0.py

@@ -2394,11 +2394,10 @@ def revert_script(document):
 
 def convert_use_xetex(document):
     " convert \\use_xetex to \\use_non_tex_fonts "
-    i = 0
     i = find_token(document.header, "\\use_xetex", 0)
     if i == -1:
-        return
-    
+        document.header.insert(-1, "\\use_non_tex_fonts 0")
+    else:
         val = get_value(document.header, "\\use_xetex", 0)
         document.header[i] = "\\use_non_tex_fonts " + val
 

lib/lyx2lyx/lyx_2_1.py

@@ -1440,6 +1440,10 @@ def revert_mdnomath(document):
                 document.header[i] = "\\font_roman %s" % mathdesign_dict[val]
 
 
+def convert_mathfonts(document):
+    document.header.insert(-1, "\\font_math auto")
+
+
 def convert_mdnomath(document):
     " Change mathdesign font name " 
 
@@ -4826,7 +4830,7 @@ convert = [
            [437, []],
            [438, []],
            [439, []],
-           [440, []],
+           [440, [convert_mathfonts]],
            [441, [convert_mdnomath]],
            [442, []],
            [443, []],

lib/lyx2lyx/lyx_2_2.py

@@ -2010,8 +2010,11 @@ def convert_fontsettings(document):
         i = find_token(document.header, f + " ", 0)
         if i == -1:
             document.warning("Malformed LyX document: No " + f + "!")
-            j = j + 1
-            continue
+            # we can fix that
+            # note that with i = -1, this will insert at the end
+            # of the header
+            value = fontdefaults[j]
+        else:
             value = document.header[i][len(f):].strip()
         if fontquotes[j]:
             if use_non_tex_fonts == "true":