_source loaders should all be nocache

When we image_new_from_source, the source object has some of the loader
state: it tracks the current read position of the load library. This
means that we mustn't keep source loaders in the operation cache, since
a second call could give a different result because the source object
read position might have changed.

Also: add a rewind to get_flags_source in spngload, and jp2k needs to
tag its load region as having no thread ownership or you'll get assert
fails in the test suite with debug enabled.

libvips/foreign/csvload.c

@@ -642,6 +642,7 @@ vips_foreign_load_csv_source_class_init( VipsForeignLoadCsvFileClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -650,6 +651,8 @@ vips_foreign_load_csv_source_class_init( VipsForeignLoadCsvFileClass *class )
 	object_class->nickname = "csvload_source";
 	object_class->build = vips_foreign_load_csv_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_csv_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/fitsload.c

@@ -316,6 +316,7 @@ vips_foreign_load_fits_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -325,6 +326,8 @@ vips_foreign_load_fits_source_class_init(
 	object_class->description = _( "load FITS from a source" );
 	object_class->build = vips_foreign_load_fits_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = 
 		vips_foreign_load_fits_source_is_a_source;
 

libvips/foreign/foreign.c

@@ -725,6 +725,11 @@ vips_foreign_find_load_source( VipsSource *source )
 		return( NULL );
 	}
 
+	/* All source loaders should be NOCACHE.
+	 */
+	g_assert( VIPS_OPERATION_CLASS( load_class )->flags & 
+		VIPS_OPERATION_NOCACHE );
+
 	return( G_OBJECT_CLASS_NAME( load_class ) );
 }
 

libvips/foreign/heifload.c

@@ -1288,6 +1288,7 @@ vips_foreign_load_heif_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -1296,6 +1297,8 @@ vips_foreign_load_heif_source_class_init(
 	object_class->nickname = "heifload_source";
 	object_class->build = vips_foreign_load_heif_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_heif_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/jp2kload.c

@@ -1209,6 +1209,7 @@ vips_foreign_load_jp2k_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -1217,6 +1218,8 @@ vips_foreign_load_jp2k_source_class_init(
 	object_class->nickname = "jp2kload_source";
 	object_class->build = vips_foreign_load_jp2k_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_jp2k_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/jp2ksave.c

@@ -880,9 +880,11 @@ vips_foreign_save_jp2k_build( VipsObject *object )
 	if( !(jp2k->accumulate = VIPS_ARRAY( NULL, sizeof_line, VipsPel )) )
 		return( -1 );
 
-	/* The line of tiles we are building.
+	/* The line of tiles we are building. It's used by the bg thread, so
+	 * no ownership.
 	 */
 	jp2k->strip = vips_region_new( save->ready );
+        vips__region_no_ownership( jp2k->strip );
 
 	/* Position strip at the top of the image, the height of a row of
 	 * tiles.

libvips/foreign/jpegload.c

@@ -250,6 +250,7 @@ vips_foreign_load_jpeg_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -259,6 +260,8 @@ vips_foreign_load_jpeg_source_class_init(
 	object_class->description = _( "load image from jpeg source" );
 	object_class->build = vips_foreign_load_jpeg_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_jpeg_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/jxlload.c

@@ -914,6 +914,7 @@ vips_foreign_load_jxl_source_class_init( VipsForeignLoadJxlSourceClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -922,6 +923,8 @@ vips_foreign_load_jxl_source_class_init( VipsForeignLoadJxlSourceClass *class )
 	object_class->nickname = "jxlload_source";
 	object_class->build = vips_foreign_load_jxl_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_jxl_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/matrixload.c

@@ -449,6 +449,7 @@ vips_foreign_load_matrix_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -457,6 +458,8 @@ vips_foreign_load_matrix_source_class_init(
 	object_class->nickname = "matrixload_source";
 	object_class->build = vips_foreign_load_matrix_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_matrix_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/niftiload.c

@@ -767,6 +767,7 @@ vips_foreign_load_nifti_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -776,6 +777,8 @@ vips_foreign_load_nifti_source_class_init(
 	object_class->description = _( "load NIfTI volumes" );
 	object_class->build = vips_foreign_load_nifti_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = 
 		vips_foreign_load_nifti_source_is_a_source;
 

libvips/foreign/nsgifload.c

@@ -853,6 +853,7 @@ vips_foreign_load_nsgif_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -862,6 +863,8 @@ vips_foreign_load_nsgif_source_class_init(
 	object_class->description = _( "load gif from source" );
 	object_class->build = vips_foreign_load_nsgif_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_nsgif_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/openslideload.c

@@ -1053,6 +1053,7 @@ vips_foreign_load_openslide_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -1062,6 +1063,8 @@ vips_foreign_load_openslide_source_class_init(
 	object_class->description = _( "load source with OpenSlide" );
 	object_class->build = vips_foreign_load_openslide_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = 
 		vips_foreign_load_openslide_source_is_a_source;
 

libvips/foreign/pdfiumload.c

@@ -921,6 +921,7 @@ vips_foreign_load_pdf_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -930,6 +931,8 @@ vips_foreign_load_pdf_source_class_init(
 	object_class->description = _( "load PDF from source" );
 	object_class->build = vips_foreign_load_pdf_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_pdf_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/pngload.c

@@ -223,6 +223,7 @@ vips_foreign_load_png_source_class_init( VipsForeignLoadPngSourceClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -232,6 +233,8 @@ vips_foreign_load_png_source_class_init( VipsForeignLoadPngSourceClass *class )
 	object_class->description = _( "load png from source" );
 	object_class->build = vips_foreign_load_png_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_png_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/popplerload.c

@@ -815,6 +815,7 @@ vips_foreign_load_pdf_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -824,6 +825,8 @@ vips_foreign_load_pdf_source_class_init(
 	object_class->description = _( "load PDF from source" );
 	object_class->build = vips_foreign_load_pdf_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_pdf_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/ppmload.c

@@ -872,6 +872,7 @@ vips_foreign_load_ppm_source_class_init( VipsForeignLoadPpmFileClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -880,6 +881,8 @@ vips_foreign_load_ppm_source_class_init( VipsForeignLoadPpmFileClass *class )
 	object_class->nickname = "ppmload_source";
 	object_class->build = vips_foreign_load_ppm_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_ppm_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/radload.c

@@ -184,6 +184,7 @@ vips_foreign_load_rad_source_class_init( VipsForeignLoadRadSourceClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -193,6 +194,8 @@ vips_foreign_load_rad_source_class_init( VipsForeignLoadRadSourceClass *class )
 	object_class->description = _( "load rad from source" );
 	object_class->build = vips_foreign_load_rad_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_rad_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/spngload.c

@@ -127,6 +127,8 @@ vips_foreign_load_png_get_flags_source( VipsSource *source )
 
 	ctx = spng_ctx_new( SPNG_CTX_IGNORE_ADLER32 );
 	spng_set_crc_action( ctx, SPNG_CRC_USE, SPNG_CRC_USE );
+	if( vips_source_rewind( source ) ) 
+		return( 0 );
 	spng_set_png_stream( ctx, 
 		vips_foreign_load_png_stream, source );
 	if( spng_get_ihdr( ctx, &ihdr ) ) {
@@ -533,12 +535,12 @@ vips_foreign_load_png_generate( VipsRegion *or,
 	}
 
 	for( y = 0; y < r->height; y++ ) {
-		error = spng_decode_row( png->ctx, 
-			VIPS_REGION_ADDR( or, 0, r->top + y ),
-			VIPS_REGION_SIZEOF_LINE( or ) );
 		/* libspng returns EOI when successfully reading the 
 		 * final line of input.
 		 */
+		error = spng_decode_row( png->ctx, 
+			VIPS_REGION_ADDR( or, 0, r->top + y ),
+			VIPS_REGION_SIZEOF_LINE( or ) );
 		if( error != 0 &&
 			error != SPNG_EOI ) { 
 			/* We've failed to read some pixels. Knock this 
@@ -739,6 +741,7 @@ vips_foreign_load_png_source_class_init( VipsForeignLoadPngSourceClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -748,6 +751,8 @@ vips_foreign_load_png_source_class_init( VipsForeignLoadPngSourceClass *class )
 	object_class->description = _( "load png from source" );
 	object_class->build = vips_foreign_load_png_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_png_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/svgload.c

@@ -626,6 +626,7 @@ vips_foreign_load_svg_source_class_init( VipsForeignLoadSvgSourceClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -634,6 +635,8 @@ vips_foreign_load_svg_source_class_init( VipsForeignLoadSvgSourceClass *class )
 	object_class->nickname = "svgload_source";
 	object_class->description = _( "load svg from source" );
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_svg_source_is_a_source;
 	load_class->header = vips_foreign_load_svg_source_header;
 	load_class->load = vips_foreign_load_svg_source_load;

libvips/foreign/tiffload.c

@@ -272,6 +272,7 @@ vips_foreign_load_tiff_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -281,6 +282,8 @@ vips_foreign_load_tiff_source_class_init(
 	object_class->description = _( "load tiff from source" );
 	object_class->build = vips_foreign_load_tiff_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips_foreign_load_tiff_source_is_a_source;
 
 	VIPS_ARG_OBJECT( class, "source", 1,

libvips/foreign/vipsload.c

@@ -287,6 +287,7 @@ vips_foreign_load_vips_source_class_init( VipsForeignLoadVipsClass *class )
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -296,6 +297,8 @@ vips_foreign_load_vips_source_class_init( VipsForeignLoadVipsClass *class )
 	object_class->description = _( "load vips from source" );
 	object_class->build = vips_foreign_load_vips_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = 
 		vips_foreign_load_vips_source_is_a_source;
 

libvips/foreign/webpload.c

@@ -254,6 +254,7 @@ vips_foreign_load_webp_source_class_init(
 {
 	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
 	VipsObjectClass *object_class = (VipsObjectClass *) class;
+	VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
 	VipsForeignLoadClass *load_class = (VipsForeignLoadClass *) class;
 
 	gobject_class->set_property = vips_object_set_property;
@@ -263,6 +264,8 @@ vips_foreign_load_webp_source_class_init(
 	object_class->description = _( "load webp from source" );
 	object_class->build = vips_foreign_load_webp_source_build;
 
+	operation_class->flags = VIPS_OPERATION_NOCACHE;
+
 	load_class->is_a_source = vips__iswebp_source; 
 
 	VIPS_ARG_OBJECT( class, "source", 1,