Changeset 272909 in webkit

Timestamp:

Feb 16, 2021 9:26:02 AM (17 months ago)

Author:

weinig@apple.com

Message:

lab() and lch() are not clamping out of bounds values at parse time
​https://bugs.webkit.org/show_bug.cgi?id=221947

Reviewed by Simon Fraser.

The model level assertions caught this (yay). The spec requires that we
clamp negative lightness values to 0 for lab(), lch() and color(lab)
and negative chroma values to 0 for lch().

Source/WebCore:

• css/parser/CSSPropertyParserHelpers.cpp:

(WebCore::CSSPropertyParserHelpers::parseLabParameters):
(WebCore::CSSPropertyParserHelpers::parseLCHParameters):
(WebCore::CSSPropertyParserHelpers::parseColorFunctionForLabParameters):

LayoutTests:

• fast/css/parsing-lab-colors-expected.txt:
• fast/css/parsing-lab-colors.html:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/css/parsing-lab-colors-expected.txt (modified) (3 diffs)
• LayoutTests/fast/css/parsing-lab-colors.html (modified) (3 diffs)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/css/parser/CSSPropertyParserHelpers.cpp (modified) (3 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2021-02-16  Sam Weinig  <weinig@apple.com>
+
+        lab() and lch() are not clamping out of bounds values at parse time
+        https://bugs.webkit.org/show_bug.cgi?id=221947
+
+        Reviewed by Simon Fraser.
+
+        The model level assertions caught this (yay). The spec requires that we
+        clamp negative lightness values to 0 for lab(), lch() and color(lab)
+        and negative chroma values to 0 for lch().
+
+        * fast/css/parsing-lab-colors-expected.txt:
+        * fast/css/parsing-lab-colors.html:
+
 2021-02-16  Chris Gambrell  <cgambrell@apple.com>
 

trunk/LayoutTests/fast/css/parsing-lab-colors-expected.txt

@@ -16 +16 @@
 PASS computedStyle("background-color", "lab(0% 0 0 / 110%)") is "lab(0% 0 0)"
 PASS computedStyle("background-color", "lab(0% 0 0 / 300%)") is "lab(0% 0 0)"
+PASS computedStyle("background-color", "lab(-40% 0 0)") is "lab(0% 0 0)"
+PASS computedStyle("background-color", "lab(50% -20 0)") is "lab(50% -20 0)"
+PASS computedStyle("background-color", "lab(50% 0 -20)") is "lab(50% 0 -20)"
 
 lch()
@@ -31 +34 @@
 PASS computedStyle("background-color", "lch(10% 20 740deg)") is "lab(10% 18.793852 6.8404026)"
 PASS computedStyle("background-color", "lch(10% 20 -700deg)") is "lab(10% 18.793852 6.8404026)"
+PASS computedStyle("background-color", "lch(-40% 0 0)") is "lab(0% 0 0)"
+PASS computedStyle("background-color", "lch(20% -20 0)") is "lab(20% 0 0)"
 PASS computedStyle("background-color", "lch(0% 0 0 / 0.5)") is "lab(0% 0 0 / 0.5)"
 PASS computedStyle("background-color", "lch(10% 20 20 / 110%)") is "lab(10% 18.793852 6.8404026)"
@@ -53 +58 @@
 PASS computedStyle("background-color", "color(lab 50% / 0.5)") is "lab(50% 0 0 / 0.5)"
 PASS computedStyle("background-color", "color(lab / 0.5)") is "lab(0% 0 0 / 0.5)"
+PASS computedStyle("background-color", "color(lab -40% 0 0)") is "lab(0% 0 0)"
+PASS computedStyle("background-color", "color(lab 50% -20 0)") is "lab(50% -20 0)"
+PASS computedStyle("background-color", "color(lab 50% 0 -20)") is "lab(50% 0 -20)"
 
 Test invalid values

trunk/LayoutTests/fast/css/parsing-lab-colors.html

@@ -47 +47 @@
     testComputed("background-color", "lab(0% 0 0 / 110%)", "lab(0% 0 0)");
     testComputed("background-color", "lab(0% 0 0 / 300%)", "lab(0% 0 0)");
+    testComputed("background-color", "lab(-40% 0 0)", "lab(0% 0 0)");
+    testComputed("background-color", "lab(50% -20 0)", "lab(50% -20 0)");
+    testComputed("background-color", "lab(50% 0 -20)", "lab(50% 0 -20)");
 
     debug('');
@@ -63 +66 @@
     testComputed("background-color", "lch(10% 20 740deg)", "lab(10% 18.793852 6.8404026)");
     testComputed("background-color", "lch(10% 20 -700deg)", "lab(10% 18.793852 6.8404026)");
+    testComputed("background-color", "lch(-40% 0 0)", "lab(0% 0 0)");
+    testComputed("background-color", "lch(20% -20 0)", "lab(20% 0 0)");
     // hue (the third argument) can be either an angle or number, with number interpreted as degrees.
     testComputed("background-color", "lch(0% 0 0 / 0.5)", "lab(0% 0 0 / 0.5)"); 
@@ -87 +92 @@
     testComputed("background-color", "color(lab 50% / 0.5)", "lab(50% 0 0 / 0.5)");
     testComputed("background-color", "color(lab / 0.5)", "lab(0% 0 0 / 0.5)");
+    testComputed("background-color", "color(lab -40% 0 0)", "lab(0% 0 0)");
+    testComputed("background-color", "color(lab 50% -20 0)", "lab(50% -20 0)");
+    testComputed("background-color", "color(lab 50% 0 -20)", "lab(50% 0 -20)");
 
     debug('');

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2021-02-16  Sam Weinig  <weinig@apple.com>
+
+        lab() and lch() are not clamping out of bounds values at parse time
+        https://bugs.webkit.org/show_bug.cgi?id=221947
+
+        Reviewed by Simon Fraser.
+
+        The model level assertions caught this (yay). The spec requires that we
+        clamp negative lightness values to 0 for lab(), lch() and color(lab)
+        and negative chroma values to 0 for lch().
+
+        * css/parser/CSSPropertyParserHelpers.cpp:
+        (WebCore::CSSPropertyParserHelpers::parseLabParameters):
+        (WebCore::CSSPropertyParserHelpers::parseLCHParameters):
+        (WebCore::CSSPropertyParserHelpers::parseColorFunctionForLabParameters):
+
 2021-02-16  Alex Christensen  <achristensen@webkit.org>
 

trunk/Source/WebCore/css/parser/CSSPropertyParserHelpers.cpp

@@ -927 +927 @@
         return { };
 
-    return Lab<float> { static_cast<float>(*lightness), static_cast<float>(*aValue), static_cast<float>(*bValue), static_cast<float>(*alpha) };
+    auto normalizedLightness = std::max(0.0, *lightness);
+
+    return Lab<float> { static_cast<float>(normalizedLightness), static_cast<float>(*aValue), static_cast<float>(*bValue), static_cast<float>(*alpha) };
 }
 
@@ -954 +956 @@
         return { };
 
+    auto normalizedLightness = std::max(0.0, *lightness);
+    auto normalizedChroma = std::max(0.0, *chroma);
     auto normalizedHue = normalizeHue(*hue);
 
-    return convertColor<Lab<float>>(LCHA<float> { static_cast<float>(*lightness), static_cast<float>(*chroma), static_cast<float>(normalizedHue), static_cast<float>(*alpha) });
+    return convertColor<Lab<float>>(LCHA<float> { static_cast<float>(normalizedLightness), static_cast<float>(normalizedChroma), static_cast<float>(normalizedHue), static_cast<float>(*alpha) });
 }
 
@@ -1006 +1010 @@
         return { };
 
-    return Lab<float> { static_cast<float>(channels[0]), static_cast<float>(channels[1]), static_cast<float>(channels[2]), static_cast<float>(*alpha) };
+    auto normalizedLightness = std::max(0.0, channels[0]);
+
+    return Lab<float> { static_cast<float>(normalizedLightness), static_cast<float>(channels[1]), static_cast<float>(channels[2]), static_cast<float>(*alpha) };
 }