Fix rgb2hsl miscalculation + add according test case

 * the fourth quadrant hue calculation had a typo for the rgb2hsl
   function. fixed now.
 * added testcase that break before, and works now

2 files changed, 3 insertions, 1 deletions

diff --git a/basegfx/source/color/bcolortools.cxx b/basegfx/source/color/bcolortools.cxx
index 1c7d2b222fff..960ccfad4d67 100644
--- a/basegfx/source/color/bcolortools.cxx
+++ b/basegfx/source/color/bcolortools.cxx
@@ -65,7 +65,7 @@ namespace basegfx { namespace tools
             else if( g == maxVal )
                 h = 2.0 + (b - r)/d;
             else
-                h = 4.0 + (r - h)/d;
+                h = 4.0 + (r - g)/d;
 
             h *= 60.0;
 
diff --git a/basegfx/test/basegfx2d.cxx b/basegfx/test/basegfx2d.cxx
index 0dfb3a8ea999..d8b574769554 100644
--- a/basegfx/test/basegfx2d.cxx
+++ b/basegfx/test/basegfx2d.cxx
@@ -1345,6 +1345,8 @@ public:
                                tools::rgb2hsl(maMagenta) == BColor(300,1,0.5));
         CPPUNIT_ASSERT_MESSAGE("cyan",
                                tools::rgb2hsl(maCyan) == BColor(180,1,0.5));
+        CPPUNIT_ASSERT_MESSAGE("third hue case",
+                               tools::rgb2hsl(BColor(0,0.5,1)) == BColor(210,1,0.5));
 
         CPPUNIT_ASSERT_MESSAGE("roundtrip white",
                                tools::hsl2rgb(tools::rgb2hsl(maWhite)) == maWhite);