add fail-on to thumbnail

see https://github.com/libvips/libvips/discussions/2781

ChangeLog

@@ -18,6 +18,7 @@
 - update libnsgif API [tlsa]
 - deprecate "properties" option to dzsave (now always on)
 - always set the min stack size for pthreads, if we can
+- add fail-on to thumbnail
 
 26/11/21 started 8.12.3
 - better arg checking for hist_find_ndim [travisbell]

libvips/resample/thumbnail.c

@@ -35,6 +35,8 @@
  * 	  mode
  * 14/4/22
  * 	- add a seq to thumbnail_image to stop cache thrashing
+ * 28/4/22
+ * 	- add fail-on
  */
 
 /*
@@ -113,6 +115,7 @@ typedef struct _VipsThumbnail {
 	char *export_profile;
 	char *import_profile;
 	VipsIntent intent;
+	VipsFailOn fail_on;
 
 	/* Bits of info we read from the input image when we get the header of
 	 * the original.
@@ -1017,6 +1020,13 @@ vips_thumbnail_class_init( VipsThumbnailClass *class )
 		G_STRUCT_OFFSET( VipsThumbnail, intent ),
 		VIPS_TYPE_INTENT, VIPS_INTENT_RELATIVE );
 
+	VIPS_ARG_ENUM( class, "fail-on", 121, 
+		_( "Fail on" ), 
+		_( "Error level to fail on" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT,
+		G_STRUCT_OFFSET( VipsThumbnail, fail_on ),
+		VIPS_TYPE_FAIL_ON, VIPS_FAIL_ON_NONE ); 
+
 	/* BOOL args which default TRUE arguments don't work with the 
 	 * command-line -- GOption does not allow --auto-rotate=false.
 	 *
@@ -1039,6 +1049,7 @@ vips_thumbnail_init( VipsThumbnail *thumbnail )
 	thumbnail->height = 1;
 	thumbnail->auto_rotate = TRUE;
 	thumbnail->intent = VIPS_INTENT_RELATIVE;
+	thumbnail->fail_on = VIPS_FAIL_ON_NONE;
 }
 
 typedef struct _VipsThumbnailFile {
@@ -1084,6 +1095,7 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, double factor )
 	if( vips_isprefix( "VipsForeignLoadJpeg", thumbnail->loader ) ) {
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
+			"fail-on", thumbnail->fail_on,
 			"shrink", (int) factor,
 			NULL ) );
 	}
@@ -1091,6 +1103,7 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, double factor )
 		thumbnail->loader ) ) {
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
+			"fail-on", thumbnail->fail_on,
 			"level", (int) factor,
 			NULL ) );
 	}
@@ -1099,6 +1112,7 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, double factor )
 		vips_isprefix( "VipsForeignLoadWebp", thumbnail->loader ) ) {
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
+			"fail-on", thumbnail->fail_on,
 			"scale", 1.0 / factor,
 			NULL ) );
 	}
@@ -1108,6 +1122,7 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, double factor )
 		if( thumbnail->page_pyramid )
 			return( vips_image_new_from_file( file->filename, 
 				"access", VIPS_ACCESS_SEQUENTIAL,
+				"fail-on", thumbnail->fail_on,
 				"page", (int) factor,
 				NULL ) );
 		else
@@ -1122,27 +1137,32 @@ vips_thumbnail_file_open( VipsThumbnail *thumbnail, double factor )
 		if( thumbnail->subifd_pyramid )
 			return( vips_image_new_from_file( file->filename, 
 				"access", VIPS_ACCESS_SEQUENTIAL,
+				"fail-on", thumbnail->fail_on,
 				"subifd", (int) factor,
 				NULL ) );
 		else if( thumbnail->page_pyramid )
 			return( vips_image_new_from_file( file->filename, 
 				"access", VIPS_ACCESS_SEQUENTIAL,
+				"fail-on", thumbnail->fail_on,
 				"page", (int) factor,
 				NULL ) );
 		else
 			return( vips_image_new_from_file( file->filename, 
 				"access", VIPS_ACCESS_SEQUENTIAL,
+				"fail-on", thumbnail->fail_on,
 				NULL ) );
 	}
 	else if( vips_isprefix( "VipsForeignLoadHeif", thumbnail->loader ) ) {
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
+			"fail-on", thumbnail->fail_on,
 			"thumbnail", (int) factor,
 			NULL ) );
 	}
 	else {
 		return( vips_image_new_from_file( file->filename, 
 			"access", VIPS_ACCESS_SEQUENTIAL,
+			"fail-on", thumbnail->fail_on,
 			NULL ) );
 	}
 }
@@ -1194,6 +1214,7 @@ vips_thumbnail_file_init( VipsThumbnailFile *file )
  * * @import_profile: %gchararray, fallback import ICC profile
  * * @export_profile: %gchararray, export ICC profile
  * * @intent: #VipsIntent, rendering intent
+ * * @fail_on: #VipsFailOn, load error types to fail on
  *
  * Make a thumbnail from a file. Shrinking is done in three stages: using any
  * shrink-on-load features available in the file import library, using a block
@@ -1238,6 +1259,9 @@ vips_thumbnail_file_init( VipsThumbnailFile *file )
  * Use @intent to set the rendering intent for any ICC transform. The default
  * is #VIPS_INTENT_RELATIVE.
  *
+ * Use @fail_on to control the types of error that will cause loading to fail.
+ * The default is #VIPS_FAIL_ON_NONE, ie. thumbnail is permissive.
+ *
  * See also: vips_thumbnail_buffer().
  *
  * Returns: 0 on success, -1 on error.
@@ -1439,6 +1463,7 @@ vips_thumbnail_buffer_init( VipsThumbnailBuffer *buffer )
  * * @import_profile: %gchararray, fallback import ICC profile
  * * @export_profile: %gchararray, export ICC profile
  * * @intent: #VipsIntent, rendering intent
+ * * @fail_on: #VipsFailOn, load error types to fail on
  * * @option_string: %gchararray, extra loader options
  *
  * Exactly as vips_thumbnail(), but read from a memory buffer. One extra
@@ -1652,6 +1677,7 @@ vips_thumbnail_source_init( VipsThumbnailSource *source )
  * * @import_profile: %gchararray, fallback import ICC profile
  * * @export_profile: %gchararray, export ICC profile
  * * @intent: #VipsIntent, rendering intent
+ * * @fail_on: #VipsFailOn, load error types to fail on
  * * @option_string: %gchararray, extra loader options
  *
  * Exactly as vips_thumbnail(), but read from a source. One extra
@@ -1768,6 +1794,7 @@ vips_thumbnail_image_init( VipsThumbnailImage *image )
  * * @import_profile: %gchararray, fallback import ICC profile
  * * @export_profile: %gchararray, export ICC profile
  * * @intent: #VipsIntent, rendering intent
+ * * @fail_on: #VipsFailOn, load error types to fail on
  *
  * Exactly as vips_thumbnail(), but read from an existing image. 
  *