ICU-463 Put fix for pointer overflow back into code.

X-SVN-Rev: 2360

icu4c/source/common/unicode/unistr.h

@@ -2571,7 +2571,8 @@ UnicodeString::extract(UTextOffset start,
                int32_t length,
                char *dst,
                const char *codepage) const
-{return extract(start, length, dst, INT32_MAX, codepage);}
+// This dstSize value should prevent pointer overflow
+{return extract(start, length, dst, 0x0FFFFFFF, codepage);}
 
 inline void  
 UnicodeString::extractBetween(UTextOffset start, 

icu4c/source/common/unistr.cpp

@@ -1251,10 +1251,9 @@ UnicodeString::extract(UTextOffset start,
 
 
   /* Pin the limit to U_MAX_PTR.  NULL check is for AS/400. */
-  /* [grhoten] What sort of silly assumption is this? */
-/*  if((myTargetLimit < myTarget) || (myTargetLimit == NULL)) {
+  if((myTargetLimit < myTarget) || (myTargetLimit == NULL)) {
     myTargetLimit = (char*)U_MAX_PTR;
-  }*/
+  }
 
   if (myTarget != NULL) {
     ucnv_fromUnicode(converter, &myTarget, myTargetLimit,