Add tests for subsurfaces and fix bug found by them

* subcompositor.c (ViewInsert, ViewInsertAfter)
(ViewInsertBefore): Update bounds for child, not parent view.
* tests/Imakefile (SRCS1, OBJS1): Build imgview first.
(SRCS6, OBJS6): Add subcompositor tests.
(PROGRAMS): Add subsurface_test.
(subsurface_test): New program target.
* tests/run_tests.sh (standard_tests): Add subsurface_test.
* tests/svnignore.txt: Add subsurface_test.
* tests/test_harness.c (swizzle_png_row_premultiply): New
function.
(load_png_image): Premultiply images w/ alpha channel.
* tests/test_harness.h: Include more headers.

subcompositor.c

@@ -1116,7 +1116,7 @@ ViewInsert (View *view, View *child)
   ViewRecomputeChildren (child, NULL);
 
   /* And update bounds.  */
-  ViewUpdateBoundsForInsert (view);
+  ViewUpdateBoundsForInsert (child);
 
   /* Now, if the subcompositor is still not garbaged, damage each
      inferior of the view.  */
@@ -1168,7 +1168,7 @@ ViewInsertAfter (View *view, View *child, View *sibling)
   ViewRecomputeChildren (child, NULL);
 
   /* And update bounds.  */
-  ViewUpdateBoundsForInsert (view);
+  ViewUpdateBoundsForInsert (child);
 
   /* Now, if the subcompositor is still not garbaged, damage each
      inferior of the view.  */
@@ -1199,7 +1199,7 @@ ViewInsertBefore (View *view, View *child, View *sibling)
 
   /* Update subcompositor bounds.  Inserting a view cannot shrink
      anything.  */
-  ViewUpdateBoundsForInsert (view);
+  ViewUpdateBoundsForInsert (child);
 
   /* Now, if the subcompositor is still not garbaged, damage each
      inferior of the view.  */

tests/Imakefile

@@ -22,18 +22,20 @@ name.c: $(12TO11ROOT)/name.xml name.h                         @@\
 ScannerTarget(12to11-test)
 ScannerTarget(viewporter)
 
-          SRCS1 = $(COMMONSRCS) simple_test.c
-          OBJS1 = $(COMMONOBJS) simple_test.o
-          SRCS2 = $(COMMONSRCS) damage_test.c
-          OBJS2 = $(COMMONOBJS) damage_test.o
-          SRCS3 = $(COMMONSRCS) transform_test.c
-          OBJS3 = $(COMMONSRCS) transform_test.o
-          SRCS4 = $(COMMONSRCS) viewporter_test.c
-          OBJS4 = $(COMMONSRCS) viewporter_test.o
           /* Not actually a test.  */
-          SRCS5 = $(COMMONSRCS) imgview.c
+          SRCS1 = $(COMMONSRCS) imgview.c
-          OBJS5 = $(COMMONSRCS) imgview.o
+          OBJS1 = $(COMMONSRCS) imgview.o
-       PROGRAMS = simple_test damage_test transform_test viewporter_test imgview
+          SRCS2 = $(COMMONSRCS) simple_test.c
+          OBJS2 = $(COMMONOBJS) simple_test.o
+          SRCS3 = $(COMMONSRCS) damage_test.c
+          OBJS3 = $(COMMONOBJS) damage_test.o
+          SRCS4 = $(COMMONSRCS) transform_test.c
+          OBJS4 = $(COMMONSRCS) transform_test.o
+          SRCS5 = $(COMMONSRCS) viewporter_test.c
+          OBJS5 = $(COMMONSRCS) viewporter_test.o
+          SRCS6 = $(COMMONSRCS) subsurface_test.c
+          OBJS6 = $(COMMONSRCS) subsurface_test.o
+       PROGRAMS = imgview simple_test damage_test transform_test viewporter_test subsurface_test
 
 /* Make all objects depend on HEADER.  */
 $(OBJS1): $(HEADER)
@@ -41,12 +43,13 @@ $(OBJS1): $(HEADER)
 /* And depend on all sources and headers.  */
 depend:: $(HEADER) $(SRCS1)
 
-NormalProgramTarget(simple_test,$(OBJS1),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(imgview,$(OBJS1),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
-NormalProgramTarget(damage_test,$(OBJS2),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(simple_test,$(OBJS2),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
-NormalProgramTarget(transform_test,$(OBJS3),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(damage_test,$(OBJS3),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
-NormalProgramTarget(viewporter_test,$(OBJS4),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(transform_test,$(OBJS4),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
-NormalProgramTarget(imgview,$(OBJS5),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(viewporter_test,$(OBJS5),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
+NormalProgramTarget(subsurface_test,$(OBJS6),NullParameter,$(LOCAL_LIBRARIES),NullParameter)
 DependTarget3($(SRCS1),$(SRCS2),$(SRCS3))
-DependTarget3($(SRCS4),$(SRCS5),NullParameter)
+DependTarget3($(SRCS4),$(SRCS5),$(SRCS6))
 
 all:: $(PROGRAMS)

tests/run_tests.sh

@@ -19,7 +19,10 @@
 # along with 12to11.  If not, see <https://www.gnu.org/licenses/>.
 
 pushd "$(dirname $0)"
-declare -a standard_tests=( simple_test damage_test transform_test viewporter_test )
+declare -a standard_tests=(
+    simple_test damage_test transform_test viewporter_test
+    subsurface_test
+)
 
 make -C . "${standard_tests[@]}"
 

tests/svnignore.txt

@@ -5,6 +5,7 @@ simple_test
 damage_test
 transform_test
 viewporter_test
+subsurface_test
 imgview
 reject.dump
 Makefile

tests/test_harness.c

@@ -391,6 +391,29 @@ swizzle_png_row (unsigned char *row_data, int width)
     }
 }
 
+/* Do the same, but also premultiply the individual color components
+   with the alpha.  */
+
+static void
+swizzle_png_row_premultiply (unsigned char *row_data, int width)
+{
+  int i;
+  unsigned char byte_1, byte_2, byte_3, byte_4;
+
+  for (i = 0; i < width; ++i)
+    {
+      byte_1 = row_data[i * 4 + 0];
+      byte_2 = row_data[i * 4 + 1];
+      byte_3 = row_data[i * 4 + 2];
+      byte_4 = row_data[i * 4 + 3];
+
+      row_data[i * 4 + 0] = (byte_3 * 1u * byte_4) / 255u;
+      row_data[i * 4 + 1] = (byte_2 * 1u * byte_4) / 255u;
+      row_data[i * 4 + 2] = (byte_1 * 1u * byte_4) / 255u;
+      row_data[i * 4 + 3] = byte_4;
+    }
+}
+
 /* Load a PNG image into a wl_buffer.  The image must be either
    PNG_COLOR_TYPE_RGB or PNG_COLOR_TYPE_RGB_ALPHA.  The image
    background is ignored.  */
@@ -473,8 +496,14 @@ load_png_image (struct test_display *display, const char *filename)
   png_read_end (png_ptr, NULL);
 
   for (i = 0; i < height; ++i)
+    {
       /* Swizzle the big-endian data.  */
+
+      if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+	swizzle_png_row_premultiply (row_pointers[i], width);
+      else
 	swizzle_png_row (row_pointers[i], width);
+    }
 
   /* Now, destroy the read struct and close the file.  */
   png_destroy_read_struct (&png_ptr, &info_ptr, NULL);

tests/test_harness.h

@@ -19,6 +19,8 @@ along with 12to11.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
 #include <unistd.h>
 #include <limits.h>