make FT_Set_Char_Size deal with 0-valued resolution parameter like the other one

ChangeLog

@@ -1,3 +1,9 @@
+2007-04-03  David Turner  <david@freetype.org>
+
+	* src/base/ftobjs.c (FT_Set_Char_Size): As suggested by James Cloos,
+	if one of the resolution is 0, treat it as if it was the same than
+	the other value.
+
 2007-04-02  David Turner  <david@freetype.org>
 
 	Add special code to detect `extra-light' fonts and do not snap their

src/base/ftobjs.c

@@ -2425,6 +2425,11 @@
     else if ( !char_height )
       char_height = char_width;
 
+    if (!horz_resolution)
+      horz_resolution = vert_resolution;
+    else if (!vert_resolution)
+      vert_resolution = horz_resolution;
+
     if ( char_width  < 1 * 64 )
       char_width  = 1 * 64;
     if ( char_height < 1 * 64 )