richedit: Handle missing colours in rtf colour table.

[Dylan Smith]

When a colour table entry is empty, then the default colour is used.
For an incomplete colour table entry 0 is used for the missing colours.

Previously the -1 value used internally for missing colours was being
converted into white, where it should be using the default colour that
is normally black.

This bug could be seen by loading the following rich text into wordpad:
{\rtf{\colortbl;;}\cf1 text}
---
 dlls/riched20/editor.c |   12 ++++++++----
 dlls/riched20/reader.c |   23 +++++++++++++----------
 2 files changed, 21 insertions(+), 14 deletions(-)
-------------- next part --------------
diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index 4cd72c8..1d6e53c 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -422,7 +422,10 @@ void ME_RTFCharAttrHook(RTF_Info *info)
       else if (info->rtfParam != rtfNoParam)
       {
         RTFColor *c = RTFGetColor(info, info->rtfParam);
-        fmt.crTextColor = (c->rtfCBlue<<16)|(c->rtfCGreen<<8)|(c->rtfCRed);
+        if (c && c->rtfCBlue >= 0)
+          fmt.crTextColor = (c->rtfCBlue<<16)|(c->rtfCGreen<<8)|(c->rtfCRed);
+        else
+          fmt.dwEffects = CFE_AUTOBACKCOLOR;
       }
       break;
     case rtfForeColor:
@@ -433,10 +436,11 @@ void ME_RTFCharAttrHook(RTF_Info *info)
       else if (info->rtfParam != rtfNoParam)
       {
         RTFColor *c = RTFGetColor(info, info->rtfParam);
-        if (c)
+        if (c && c->rtfCBlue >= 0)
           fmt.crTextColor = (c->rtfCBlue<<16)|(c->rtfCGreen<<8)|(c->rtfCRed);
-        else
-          fmt.crTextColor = 0;
+        else {
+          fmt.dwEffects = CFE_AUTOCOLOR;
+        }
       }
       break;
     case rtfFontNum:
diff --git a/dlls/riched20/reader.c b/dlls/riched20/reader.c
index b6a6f44..0462f71 100644
--- a/dlls/riched20/reader.c
+++ b/dlls/riched20/reader.c
@@ -990,18 +990,21 @@ static void ReadColorTbl(RTF_Info *info)
 			break;
 		}
 		cp->rtfCNum = cnum++;
-		cp->rtfCRed = cp->rtfCGreen = cp->rtfCBlue = -1;
 		cp->rtfNextColor = info->colorList;
 		info->colorList = cp;
-		while (RTFCheckCM (info, rtfControl, rtfColorName))
-		{
-			switch (info->rtfMinor)
-			{
-			case rtfRed:	cp->rtfCRed = info->rtfParam; break;
-			case rtfGreen:	cp->rtfCGreen = info->rtfParam; break;
-			case rtfBlue:	cp->rtfCBlue = info->rtfParam; break;
-			}
-			RTFGetToken (info);
+		if (!RTFCheckCM (info, rtfControl, rtfColorName))
+			cp->rtfCRed = cp->rtfCGreen = cp->rtfCBlue = -1;
+		else {
+			cp->rtfCRed = cp->rtfCGreen = cp->rtfCBlue = 0;
+			do {
+				switch (info->rtfMinor)
+				{
+				case rtfRed:	cp->rtfCRed = info->rtfParam & 0xFF; break;
+				case rtfGreen:	cp->rtfCGreen = info->rtfParam & 0xFF; break;
+				case rtfBlue:	cp->rtfCBlue = info->rtfParam & 0xFF; break;
+				}
+				RTFGetToken (info);
+			} while (RTFCheckCM (info, rtfControl, rtfColorName));
 		}
 		if (info->rtfClass == rtfEOF)
 			break;