[cff] Fix segfault on missing `psaux' (#52218)

* src/cff/cffload.c (cff_done_blend): Add a check for possible nullptr.

* modules.cfg: Update dependency list.

ChangeLog

@@ -1,3 +1,11 @@
+2017-10-12  Ewald Hew  <ewaldhew@gmail.com>
+
+	[cff] Fix segfault on missing `psaux' (#52218)
+
+	* src/cff/cffload.c (cff_done_blend): Add a check for possible nullptr.
+
+	* modules.cfg: Update dependency list.
+
 2017-10-15  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	[base, cff] Fix MSVC warnings.

modules.cfg

@@ -42,7 +42,7 @@ FONT_MODULES += type1
 
 # CFF/OpenType font driver.
 #
-# This driver needs the `sfnt', `pshinter', and `psnames' modules.
+# This driver needs the `sfnt', `psaux', `pshinter', and `psnames' modules.
 FONT_MODULES += cff
 
 # Type 1 CID-keyed font driver.

src/cff/cffload.c

@@ -1595,7 +1595,8 @@
     FT_Service_MultiMasters  mm = (FT_Service_MultiMasters)face->mm;
 
 
-    mm->done_blend( FT_FACE( face ) );
+    if (mm)
+      mm->done_blend( FT_FACE( face ) );
   }
 
 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */