Update IndexOfOrdinalIgnoreCase to use full code units

Author: stephentoub

src/corefx/System.Globalization.Native/collation.cpp

@@ -129,78 +129,73 @@ extern "C" int32_t LastIndexOf(
 Static Function:
 AreEqualOrdinalIgnoreCase
 */
-static bool AreEqualOrdinalIgnoreCase(UChar one, UChar two)
+static bool AreEqualOrdinalIgnoreCase(UChar32 one, UChar32 two)
 {
-	// Return whether the two characters are identical or would be identical if they were upper-cased.
-
-	if (one == two)
-	{
-		return true;
-	}
-
-	if (one == 0x0131 || two == 0x0131)
-	{
-		// On Windows with InvariantCulture, the LATIN SMALL LETTER DOTLESS I (U+0131)
-		// capitalizes to itself, whereas with ICU it capitalizes to LATIN CAPITAL LETTER I (U+0049).
-		// We special case it to match the Windows invariant behavior.
-		return false;
-	}
-
-	return u_toupper(one) == u_toupper(two);
+    // Return whether the two characters are identical or would be identical if they were upper-cased.
+
+    if (one == two)
+    {
+        return true;
+    }
+
+    if (one == 0x0131 || two == 0x0131)
+    {
+        // On Windows with InvariantCulture, the LATIN SMALL LETTER DOTLESS I (U+0131)
+        // capitalizes to itself, whereas with ICU it capitalizes to LATIN CAPITAL LETTER I (U+0049).
+        // We special case it to match the Windows invariant behavior.
+        return false;
+    }
+
+    return u_toupper(one) == u_toupper(two);
 }
 
 /*
 Function:
 IndexOfOrdinalIgnoreCase
 */
 extern "C" int32_t
-IndexOfOrdinalIgnoreCase(const UChar* lpTarget, int32_t cwTargetLength, const UChar* lpSource, int32_t cwSourceLength)
+IndexOfOrdinalIgnoreCase(
+    const UChar* lpTarget, int32_t cwTargetLength, 
+    const UChar* lpSource, int32_t cwSourceLength, 
+    int32_t findLast)
 {
-	int32_t endIndex = cwSourceLength - cwTargetLength;
-	assert(endIndex >= 0);
-
-	for (int32_t i = 0; i <= endIndex; i++)
-	{
-		int32_t targetIdx = 0;
-		for (int32_t srcIdx = i; targetIdx < cwTargetLength; srcIdx++, targetIdx++) {
-			if (!AreEqualOrdinalIgnoreCase(lpSource[srcIdx], lpTarget[targetIdx])) {
-				break;
-			}
-		}
-
-		if (targetIdx == cwTargetLength) {
-			return i;
-		}
-	}
-
-	return -1;
-}
+    int32_t result = -1;
 
-/*
-Function:
-LastIndexOfOrdinalIgnoreCase
-*/
-extern "C" int32_t
-LastIndexOfOrdinalIgnoreCase(const UChar* lpTarget, int32_t cwTargetLength, const UChar* lpSource, int32_t cwSourceLength)
-{
-	int32_t endIndex = cwSourceLength - cwTargetLength;
-	assert(endIndex >= 0);
-
-	for (int32_t i = endIndex; i >= 0; i--)
-	{
-		int32_t targetIdx = 0;
-		for (int32_t srcIdx = i; targetIdx < cwTargetLength; srcIdx++, targetIdx++) {
-			if (!AreEqualOrdinalIgnoreCase(lpSource[srcIdx], lpTarget[targetIdx])) {
-				break;
-			}
-		}
-
-		if (targetIdx == cwTargetLength) {
-			return i;
-		}
-	}
-
-	return -1;
+    int32_t endIndex = cwSourceLength - cwTargetLength;
+    assert(endIndex >= 0);
+
+    int32_t i = 0;
+    while (i <= endIndex)
+    {
+        int32_t srcIdx = i, trgIdx = 0;
+        const UChar *src = lpSource, *trg = lpTarget;
+        UChar32 srcCodepoint, trgCodepoint;
+
+        bool match = true;
+        while (trgIdx < cwTargetLength)
+        {
+            U16_NEXT(src, srcIdx, cwSourceLength, srcCodepoint);
+            U16_NEXT(trg, trgIdx, cwTargetLength, trgCodepoint);
+            if (!AreEqualOrdinalIgnoreCase(srcCodepoint, trgCodepoint))
+            {
+                match = false; 
+                break;
+            }
+        }
+
+        if (match) 
+        {
+            result = i;
+            if (!findLast)
+            {
+                break;
+            }
+        }
+
+        U16_FWD_1(lpSource, i, cwSourceLength);
+    }
+
+    return result;
 }
 
 /*

src/mscorlib/corefx/Interop/Unix/System.Globalization.Native/Interop.Collation.cs

@@ -19,10 +19,7 @@ internal static partial class GlobalizationInterop
         internal unsafe static extern int LastIndexOf(byte[] localeName, string target, char* pSource, int cwSourceLength, CompareOptions options);
 
         [DllImport(Libraries.GlobalizationInterop, CharSet = CharSet.Unicode)]
-        internal unsafe static extern int IndexOfOrdinalIgnoreCase(string target, int cwTargetLength, char* pSource, int cwSourceLength);
-
-        [DllImport(Libraries.GlobalizationInterop, CharSet = CharSet.Unicode)]
-        internal unsafe static extern int LastIndexOfOrdinalIgnoreCase(string target, int cwTargetLength, char* pSource, int cwSourceLength);
+        internal unsafe static extern int IndexOfOrdinalIgnoreCase(string target, int cwTargetLength, char* pSource, int cwSourceLength, bool findLast);
 
         [DllImport(Libraries.GlobalizationInterop, CharSet = CharSet.Unicode)]
         [return: MarshalAs(UnmanagedType.Bool)]

src/mscorlib/corefx/System/Globalization/CompareInfo.Unix.cs

@@ -39,7 +39,7 @@ internal static unsafe int IndexOfOrdinal(string source, string value, int start
             {
                 fixed (char* pSource = source)
                 {
-                    int index = Interop.GlobalizationInterop.IndexOfOrdinalIgnoreCase(value, value.Length, pSource + startIndex, count);
+                    int index = Interop.GlobalizationInterop.IndexOfOrdinalIgnoreCase(value, value.Length, pSource + startIndex, count, findLast: false);
                     return index != -1 ?
                         startIndex + index :
                         -1;
@@ -88,7 +88,7 @@ internal static unsafe int LastIndexOfOrdinal(string source, string value, int s
             {
                 fixed (char* pSource = source)
                 {
-                    int lastIndex = Interop.GlobalizationInterop.LastIndexOfOrdinalIgnoreCase(value, value.Length, pSource + leftStartIndex, count);
+                    int lastIndex = Interop.GlobalizationInterop.IndexOfOrdinalIgnoreCase(value, value.Length, pSource + leftStartIndex, count, findLast: true);
                     return lastIndex != -1 ?
                         leftStartIndex + lastIndex :
                         -1;