flush target at end of write

we were missing end-of-write flushes on four save operations

thanks harukizaemon

see https://github.com/libvips/ruby-vips/issues/256

ChangeLog

@@ -4,6 +4,7 @@
 - fix out of bounds exif read in heifload
 - fix out of bounds read in tiffload
 - fix tiffsave region shrink mode [imgifty]
+- add missing flushes on write to target [harukizaemon]
 
 6/9/20 started 8.10.2
 - update magicksave/load profile handling [kelilevi]

libvips/foreign/csvsave.c

@@ -179,6 +179,8 @@ vips_foreign_save_csv_build( VipsObject *object )
 	if( vips_sink_disc( save->ready, vips_foreign_save_csv_block, csv ) )
 		return( -1 );
 
+	vips_target_finish( csv->target );
+
 	return( 0 );
 }
 

libvips/foreign/matrixsave.c

@@ -136,6 +136,8 @@ vips_foreign_save_matrix_build( VipsObject *object )
 		vips_foreign_save_matrix_block, matrix ) )
 		return( -1 );
 
+	vips_target_finish( matrix->target );
+
 	return( 0 );
 }
 

libvips/foreign/ppmsave.c

@@ -301,6 +301,8 @@ vips_foreign_save_ppm( VipsForeignSavePpm *ppm, VipsImage *image )
 	if( vips_sink_disc( image, vips_foreign_save_ppm_block, ppm ) )
 		return( -1 );
 
+	vips_target_finish( ppm->target );
+
 	return( 0 );
 }
 

libvips/foreign/vipspng.c

@@ -1192,6 +1192,8 @@ write_vips( Write *write,
 
 	png_write_end( write->pPng, write->pInfo );
 
+	vips_target_finish( write->target );
+
 	return( 0 );
 }