Add `FT_Done_MM_Var'.

This is necessary in case the application's memory routines differ
from FreeType.  A typical example is a Python application on Windows
that calls FreeType compiled as a DLL via the `ctypes' interface.

* include/freetype/ftmm.h, src/base/ftmm.c (FT_Done_MM_Var): Declare
and define.

* docs/CHANGES: Updated.

ChangeLog

@@ -1,3 +1,16 @@
+2018-01-06  Werner Lemberg  <wl@gnu.org>
+
+	Add `FT_Done_MM_Var'.
+
+	This is necessary in case the application's memory routines differ
+	from FreeType.  A typical example is a Python application on Windows
+	that calls FreeType compiled as a DLL via the `ctypes' interface.
+
+	* include/freetype/ftmm.h, src/base/ftmm.c (FT_Done_MM_Var): Declare
+	and define.
+
+	* docs/CHANGES: Updated.
+
 2018-01-03  Werner Lemberg  <wl@gnu.org>
 
 	[truetype] Round offsets of glyph components only if hinting is on.

docs/CHANGES

@@ -56,6 +56,9 @@ CHANGES BETWEEN 2.8.1 and 2.8.2
       PostScript name is provided, not  looking up special entries for
       named instances.
 
+    - A new function  `FT_Done_MM_Var' is provided to  free the memory
+      returned in a call to `FT_Get_MM_Var'.
+
     - On  platforms  using  the   `configure'  script,  the  installed
       `ftoption.h' file  now correctly reflects  configuration options
       like `--with-harfbuzz'.

include/freetype/ftmm.h

@@ -286,7 +286,7 @@ FT_BEGIN_HEADER
   /* <Output>                                                              */
   /*    amaster :: The variation descriptor.                               */
   /*               Allocates a data structure, which the user must         */
-  /*               deallocate with `free' after use.                       */
+  /*               deallocate with a call to @FT_Done_MM_Var after use.    */
   /*                                                                       */
   /* <Return>                                                              */
   /*    FreeType error code.  0~means success.                             */
@@ -296,6 +296,26 @@ FT_BEGIN_HEADER
                  FT_MM_Var*  *amaster );
 
 
+  /*************************************************************************/
+  /*                                                                       */
+  /* <Function>                                                            */
+  /*    FT_Done_MM_Var                                                     */
+  /*                                                                       */
+  /* <Description>                                                         */
+  /*    Free the memory allocated by @FT_Get_MM_Var.                       */
+  /*                                                                       */
+  /* <Input>                                                               */
+  /*    library :: A handle of the face's parent library object that was   */
+  /*               used in the call to @FT_Get_MM_Var to create `amaster'. */
+  /*                                                                       */
+  /* <Return>                                                              */
+  /*    FreeType error code.  0~means success.                             */
+  /*                                                                       */
+  FT_EXPORT( FT_Error )
+  FT_Done_MM_Var( FT_Library   library,
+                  FT_MM_Var   *amaster );
+
+
   /*************************************************************************/
   /*                                                                       */
   /* <Function>                                                            */

src/base/ftmm.c

@@ -145,6 +145,25 @@
   }
 
 
+  /* documentation is in ftmm.h */
+
+  FT_EXPORT_DEF( FT_Error )
+  FT_Done_MM_Var( FT_Library  library,
+                  FT_MM_Var*  amaster )
+  {
+    FT_Memory  memory;
+
+
+    if ( !library )
+      return FT_THROW( Invalid_Library_Handle );
+
+    memory = library->memory;
+    FT_FREE( amaster );
+
+    return FT_Err_Ok;
+  }
+
+
   /* documentation is in ftmm.h */
 
   FT_EXPORT_DEF( FT_Error )