fast/text/multi-code-unit-simple-path.html This test tries to render \x11300 and expects a mismatch with an empty document (i.e. something should be rendered). For both GTK and WPE, an empty actual.png is generated, making the expected mismatch to fail. MiniBrowser correctly renders the box around the would be glyph. Forcing WTR to dump the render tree (by removing the expected html), there is a text run for the character: layer at (0,0) size 800x600 RenderView at (0,0) size 800x600 layer at (0,0) size 800x71 RenderBlock {HTML} at (0,0) size 800x71 RenderBody {BODY} at (8,8) size 784x55 RenderBlock {DIV} at (0,0) size 784x55 RenderText {#text} at (0,1) size 37x53 text run at (0,1) width 37: "\x{D804}\x{DF00}" The same failure happens with other characters where the browsers shows the placeholder box, even from the BMP (so, unrelated to the original patch from bu221356). For example, \u1800 (Mongolian block).
Created attachment 422262 [details] Pixel dump of "a᠀c" Looks like the issue is WTR not drawing the placeholder box, as this dump shows for "a᠀c". The browser correctly shows the placeholder instead of the empty space. Should WTR draw the placeholder too?
<rdar://problem/75324483>