squash compiler warnings

and rename vips_image_write_filename() to vips_image_write_to_file() to
be more consistent

ChangeLog

@@ -1,6 +1,6 @@
 20/8/11 started 7.27.0
 - version bump for new dev cycle
-- im_subtract(), im_avg(), im_min(), im_minpos() redone as classes
+- im_subtract(), im_avg(), im_min(), im_minpos(), im_copy() redone as classes
 - added VIPS_ARGUMENT_APPEND to help control arg ordering
 - generate has a 'stop' param to signal successful early termination
 - added optional output args, eg. x/y for min
@@ -18,9 +18,8 @@
 - im_csv2vips() allows quoted strings, including escaped quotes
 - added vips_shutdown()
 - added --vips-leak flag
-- added VipsCopy
 - more VipsImage props
-- added vips_image_write(), old one becomes vips_image_write_filename()
+- added vips_image_write(), old one becomes vips_image_write_to_file()
 - jpeg read/write copies over XMP data
 
 12/9/11 started 7.26.4

TODO

@@ -1,34 +1,15 @@
-- vips_image_write() uses im_copy() to send an image to a file
-
-  but im_copy() now calls vips_copy(), which can't actually write to a
-  specific descriptor!
-
-  vips_image_write() needs to do some behind-the-scenes magic, I'm not quite
-  sure what
-
-  	just vips_image_generate() with a pointer copy I think, basically
-	vipscopy without creating the output
-
-  rename as vips_image_write_to_filename(), vips_image_write() should write to
-  a VipsImage
-
-  im_add() etc. compat functions need to start calling vips_image_write() 
-  instead of im_copy()
+- improve CSV parsing a bit more, allow quotes on any field not just strings
 
 
 
-- vipscopy
 
-  how would we do meta sets?
-
-  vips_object_set_argument_from_string() needs more arg types
+- vips_object_set_argument_from_string() needs more arg types
 
   must be some way to make this more automatic
 
 
 
 
-
 - nicolas's convsep patch
 
 - add nifti support
@@ -38,21 +19,19 @@
 
 
 
-
-
 - do clip/embed etc. in new style, good to get everything that VipsAdd uses in
   the new stack
 
 
 
+
 - add vips_init_argv() which processes argc/argv for you? handy for tiny
   progs, perhaps
 
 
 
 
-
-- could we generate the code for vips_add() etc. automatically? it might be 
+- generate the code for vips_add() etc. automatically? it might be 
   nice to have them all in one place at least
 
 

libvips/include/vips/image.h

@@ -474,7 +474,7 @@ void vips_image_set_delete_on_close( VipsImage *image,
 	gboolean delete_on_close );
 VipsImage *vips_image_new_disc_temp( const char *format );
 int vips_image_write( VipsImage *image, VipsImage *out );
-int vips_image_write_filename( VipsImage *image, const char *filename );
+int vips_image_write_to_file( VipsImage *image, const char *filename );
 
 gboolean vips_image_isMSBfirst( VipsImage *image );
 gboolean vips_image_isfile( VipsImage *image );

libvips/iofuncs/image.c

@@ -326,7 +326,7 @@ vips_image_to_string( VipsObject *object, VipsBuf *buf )
 static int 
 vips_image_write_object( VipsObject *object, const char *string )
 {
-	return( vips_image_write_filename( VIPS_IMAGE( object ), string ) );
+	return( vips_image_write_to_file( VIPS_IMAGE( object ), string ) );
 }
 
 static void *
@@ -1780,8 +1780,10 @@ vips_image_write_gen( VipsRegion *or,
  * @image: image to write
  * @out: write to this image
  *
- * A convenience function to write a #VipsImage to another #VipsImage. Unlike
- * vips_copy(), you can specify the #VipsImage you want to write to.
+ * Write @image to @out. Use vips_image_new_mode() and friends to create the
+ * #VipsImage you want to write to.
+ *
+ * See also: vips_image_new_mode(), vips_copy(), vips_image_write_to_file().
  *
  * Returns: 0 on success, or -1 on error.
  */
@@ -1805,16 +1807,16 @@ vips_image_write( VipsImage *image, VipsImage *out )
 }
 
 /**
- * vips_image_write_filename:
+ * vips_image_write_to_file:
  * @image: image to write
  * @filename: write to this file
  *
- * A convenience function to write a #VipsImage to a file. 
+ * A convenience function to write @image to a file. 
  *
  * Returns: 0 on success, or -1 on error.
  */
 int
-vips_image_write_filename( VipsImage *image, const char *filename )
+vips_image_write_to_file( VipsImage *image, const char *filename )
 {
 	VipsImage *out;
 

libvips/iofuncs/operation.c

@@ -256,7 +256,7 @@ vips_operation_new( const char *name )
 		g_value_unset( &value ); \
 	} \
 	else if( (ARG_CLASS->flags & VIPS_ARGUMENT_OUTPUT) ) { \
-		void **arg; \
+		void **arg __attribute__ ((unused)); \
  		\
 		/* Output args are a pointer to where to send the \
 		 * result. \