make the Color constructors explicitly specify transparency

to reduce the churn, we leave the existing constructor in place,
and add a clang plugin to detect when the value passed to the
existing constructor may contain transparency/alpha data.

i.e. we leave expressions like Color(0xffffff) alone, but
warn about any non-constant expression, and any expression
like Color(0xff000000)

Change-Id: Id2ce58e08882d9b7bd0b9f88eca97359dcdbcc8c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109362
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 9 insertions, 1 deletions

diff --git a/include/sax/tools/converter.hxx b/include/sax/tools/converter.hxx
index 0d3d68ba301c..88cea1c33ab7 100644
--- a/include/sax/tools/converter.hxx
+++ b/include/sax/tools/converter.hxx
@@ -123,7 +123,15 @@ public:
     {
         sal_Int32 n(rColor);
         bool b = convertColor( n, rValue );
-        if (b) rColor = n;
+        if (b) rColor = Color(ColorTransparency, n);
+        return b;
+    }
+    static bool convertColor( ::Color& rColor,
+                              std::string_view rValue )
+    {
+        sal_Int32 n(rColor);
+        bool b = convertColor( n, rValue );
+        if (b) rColor = Color(ColorTransparency, n);
         return b;
     }