diff --git a/Headers/Additions/GNUstepBase/Unicode.h b/Headers/Additions/GNUstepBase/Unicode.h
index aabea0257..abd9b6385 100644
--- a/Headers/Additions/GNUstepBase/Unicode.h
+++ b/Headers/Additions/GNUstepBase/Unicode.h
@@ -64,7 +64,7 @@ GS_EXPORT unichar *uni_is_decomp(unichar u);
 #define	GSUniBOM	0x08
 #define	GSUniShortOk	0x10
 
-GS_EXPORT BOOL GSIsUnicode(const unichar *chars, unsigned length,
+GS_EXPORT unsigned GSUnicode(const unichar *chars, unsigned length,
   BOOL *isASCII, BOOL *isLatin1);
 GS_EXPORT BOOL GSFromUnicode(unsigned char **dst, unsigned int *size,
   const unichar *src, unsigned int slen, NSStringEncoding enc, NSZone *zone,
diff --git a/Source/Additions/Unicode.m b/Source/Additions/Unicode.m
index a19808f36..b55cd48c1 100644
--- a/Source/Additions/Unicode.m
+++ b/Source/Additions/Unicode.m
@@ -1094,28 +1094,29 @@ int encode_cstrtoustr(unichar *dst, int dl, const char *src, int sl,
  * Function to check a block of data for validity as a unicode string and
  * say whether it contains solely ASCII or solely Latin1 data.<br />
  * Any leading BOM must already have been removed and the data must already
- * be in native byte order.
+ * be in native byte order.<br />
+ * Returns the number of characters which were found valid.
  */
-BOOL
-GSIsUnicode(const unichar *chars, unsigned length,
+unsigned
+GSUnicode(const unichar *chars, unsigned length,
   BOOL *isASCII, BOOL *isLatin1)
 {
   unsigned	i = 0;
   unichar	c;
 
-  *isASCII = YES;
-  *isLatin1 = YES;
+  if (isASCII) *isASCII = YES;
+  if (isLatin1) *isLatin1 = YES;
   while (i < length)
     {
       if ((c = chars[i++]) > 127)
         {
-	  *isASCII = NO;
+	  if (isASCII) *isASCII = NO;
 	  i--;
 	  while (i < length)
 	    {
 	      if ((c = chars[i++]) > 255)
 		{
-		  *isLatin1 = NO;
+		  if (isLatin1) *isLatin1 = NO;
 		  i--;
 		  while (i < length)
 		    {
@@ -1123,23 +1124,23 @@ GSIsUnicode(const unichar *chars, unsigned length,
 		      if (c == 0xfffe || c == 0xffff
 			|| (c >= 0xfdd0 && c <= 0xfdef))
 			{
-			  return NO;	// Non-characters.
+			  return i - 1;	// Non-characters.
 			}
 		      if (c >= 0xdc00 && c <= 0xdfff)
 		        {
-			  return NO;	// Second half of a surrogate pair.
+			  return i - 1;	// Second half of a surrogate pair.
 		        }
 		      if (c >= 0xd800 && c <= 0xdbff)
 		        {
 			  // First half of a surrogate pair.
 			  if (i >= length)
 			    {
-			      return NO;	// Second half missing
+			      return i - 1;	// Second half missing
 			    }
 			  c = chars[i];
 			  if (c < 0xdc00 || c > 0xdfff)
 			    {
-			      return NO;	// Second half missing
+			      return i - 1;	// Second half missing
 			    }
 			  i++;		// Step past second half
 		        }
@@ -1148,7 +1149,7 @@ GSIsUnicode(const unichar *chars, unsigned length,
 	    }
         }
     }
-  return YES;
+  return i;
 }
 
 #define	GROW() \
diff --git a/Source/GSString.m b/Source/GSString.m
index 59eaef984..b692a9d69 100644
--- a/Source/GSString.m
+++ b/Source/GSString.m
@@ -358,7 +358,7 @@ setup(void)
   BOOL	isASCII;
   BOOL	isLatin1;
 
-  if (GSIsUnicode(chars, length, &isASCII, &isLatin1) == NO)
+  if (GSUnicode(chars, length, &isASCII, &isLatin1) != length)
     {
       return nil;	// Invalid data
     }
@@ -400,7 +400,7 @@ setup(void)
   BOOL	isASCII;
   BOOL	isLatin1;
 
-  if (GSIsUnicode(chars, length, &isASCII, &isLatin1) == NO)
+  if (GSUnicode(chars, length, &isASCII, &isLatin1) != length)
     {
       return nil;	// Invalid data
     }
@@ -1286,14 +1286,44 @@ dataUsingEncoding_u(GSStr self, NSStringEncoding encoding, BOOL flag)
 
   if (encoding == NSUnicodeStringEncoding)
     {
-      unichar *buff;
+      unichar	*buff;
+      unsigned	l;
+      unsigned	from = 0;
+      unsigned	to = 1;
 
+      if ((l = GSUnicode(self->_contents.u, len, 0, 0)) != len)
+        {
+	  if (flag == NO)
+	    {
+	      return nil;
+	    }
+	}
       buff = (unichar*)NSZoneMalloc(NSDefaultMallocZone(),
 	sizeof(unichar)*(len+1));
       buff[0] = 0xFEFF;
-      memcpy(buff+1, self->_contents.u, sizeof(unichar)*len);
+
+      while (len > 0)
+        {
+	  if (l > 0)
+	    {
+	      memcpy(buff + to, self->_contents.u + from, sizeof(unichar)*l);
+	      from += l;
+	      to += l;
+	      len -= l;
+	    }
+	  if (len > 0)
+	    {
+	      // A bad character in the string ... skip it.
+	      if (--len > 0)
+		{
+		  // Not at end ... try another batch.
+		  from++;
+		  l = GSUnicode(self->_contents.u + from, len, 0, 0);
+		}
+	    }
+	}
       return [NSData dataWithBytesNoCopy: buff
-				  length: sizeof(unichar)*(len+1)];
+				  length: sizeof(unichar)*to];
     }
   else
     {
@@ -3060,7 +3090,7 @@ agree, create a new GSUnicodeInlineString otherwise.
   BOOL	isASCII;
   BOOL	isLatin1;
 
-  if (GSIsUnicode(chars, length, &isASCII, &isLatin1) == NO)
+  if (GSUnicode(chars, length, &isASCII, &isLatin1) != length)
     {
       RELEASE(self);
       return nil;	// Invalid data
@@ -3120,7 +3150,7 @@ agree, create a new GSUnicodeInlineString otherwise.
   BOOL	isASCII;
   BOOL	isLatin1;
 
-  if (GSIsUnicode(chars, length, &isASCII, &isLatin1) == NO)
+  if (GSUnicode(chars, length, &isASCII, &isLatin1) != length)
     {
       RELEASE(self);
       return nil;	// Invalid data
@@ -3526,7 +3556,7 @@ agree, create a new GSUnicodeInlineString otherwise.
   BOOL	isASCII;
   BOOL	isLatin1;
 
-  if (GSIsUnicode(chars, length, &isASCII, &isLatin1) == NO)
+  if (GSUnicode(chars, length, &isASCII, &isLatin1) != length)
     {
       RELEASE(self);
       return nil;	// Invalid data