[psaux] Fix Type 1 glyphs with too many stem hints.

According to the CFF specification, charstrings can have up to 96 stem
hints. Due to hint replacement routines in Type 1 charstrings, some
glyphs are rejected by the Adobe engine, which implements the above
limit. This fix turns off hinting for such glyphs.

* src/psaux/pshints.c (cf2_hintmap_build): Reset the error from calling
`cf2_hintmask_setAll' on a problematic Type 1 charstring and turn off
hinting.

ChangeLog

@@ -1,3 +1,16 @@
+2018-01-07  Ewald Hew  <ewaldhew@gmail.com>
+
+	[psaux] Fix Type 1 glyphs with too many stem hints.
+
+	According to the CFF specification, charstrings can have up to 96 stem
+	hints. Due to hint replacement routines in Type 1 charstrings, some
+	glyphs are rejected by the Adobe engine, which implements the above
+	limit. This fix turns off hinting for such glyphs.
+
+	* src/psaux/pshints.c (cf2_hintmap_build): Reset the error from calling
+	`cf2_hintmask_setAll' on a problematic Type 1 charstring and turn off
+	hinting.
+
 2018-01-06  Werner Lemberg  <wl@gnu.org>
 
 	Add `FT_Done_MM_Var'.

src/psaux/pshints.c

@@ -842,7 +842,15 @@
                            cf2_arrstack_size( hStemHintArray ) +
                              cf2_arrstack_size( vStemHintArray ) );
       if ( !cf2_hintmask_isValid( hintMask ) )
+      {
+        if ( font->isT1 )
+        {
+          /* no error, just continue unhinted */
+          *hintMask->error = FT_Err_Ok;
+          hintmap->hinted  = FALSE;
+        }
         return;                   /* too many stem hints */
+      }
     }
 
     /* begin by clearing the map */