From 9c02edfe2d41e9bba08768aeb881f4f7a9ba5d8f Mon Sep 17 00:00:00 2001
From: Andy Heninger <andy.heninger@gmail.com>
Date: Fri, 23 May 2003 01:32:25 +0000
Subject: [PATCH] ICU-2908 fix crash on regexp patterns with quantifiers on a
 surrogate pair e.g. \ud800\udc00*

X-SVN-Rev: 12065
---
 icu4c/source/i18n/regexcmp.cpp          | 27 +++++++++++++++++++------
 icu4c/source/test/testdata/regextst.txt | 11 ++++++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/icu4c/source/i18n/regexcmp.cpp b/icu4c/source/i18n/regexcmp.cpp
index ae70f94fdf..f949527d91 100644
--- a/icu4c/source/i18n/regexcmp.cpp
+++ b/icu4c/source/i18n/regexcmp.cpp
@@ -1005,7 +1005,7 @@ UBool RegexCompile::doParseActions(EParseAction action)
         }
         break;
 
-    case doPossesiveInterval:
+    case doPossessiveInterval:
         // Finished scanning a Possessive {lower,upper}+ interval.  Generate the code for it.
         {
             // Remember the loc for the top of the block being looped over.
@@ -1215,7 +1215,7 @@ UBool RegexCompile::doParseActions(EParseAction action)
 
 
 
-    case doPossesivePlus:
+    case doPossessivePlus:
         // Possessive ++ quantifier.
         // Compiles to
         //       1.   STO_SP
@@ -1250,7 +1250,7 @@ UBool RegexCompile::doParseActions(EParseAction action)
         }
         break;
 
-    case doPossesiveStar:
+    case doPossessiveStar:
         // Possessive *+ quantifier.
         // Compiles to
         //       1.   STO_SP       loc
@@ -1286,7 +1286,7 @@ UBool RegexCompile::doParseActions(EParseAction action)
         }
         break;
 
-    case doPossesiveOpt:
+    case doPossessiveOpt:
         // Possessive  ?+ quantifier.
         //  Compiles to
         //     1. STO_SP      loc
@@ -1445,11 +1445,26 @@ void RegexCompile::literalChar(UChar32 c)  {
     // We are adding onto an existing string
     fRXPat->fLiteralText.append(c);
 
-    // If the most recently emitted op is a URX_ONECHAR, change it to a string op.
     op     = fRXPat->fCompiledPat->lastElementi();
     opType = URX_TYPE(op);
     U_ASSERT(opType == URX_ONECHAR || opType == URX_ONECHAR_I || opType == URX_STRING_LEN);
+
+    // If the most recently emitted op is a URX_ONECHAR, 
     if (opType == URX_ONECHAR || opType == URX_ONECHAR_I) {
+        if (U16_IS_TRAIL(c) && U16_IS_LEAD(URX_VAL(op))) {
+            // The most recently emitted op is a ONECHAR that was the first half
+            //   of a surrogate pair.  Update the ONECHAR's operand to be the
+            //   supplementary code point resulting from both halves of the pair.
+            c = U16_GET_SUPPLEMENTARY(URX_VAL(op), c);
+            op = URX_BUILD(opType, c);
+            patternLoc = fRXPat->fCompiledPat->size() - 1;
+            fRXPat->fCompiledPat->setElementAt(op, patternLoc);
+            return;
+        }
+        
+        // The most recently emitted op is a ONECHAR.
+        //  We've now received another adjacent char.  Change the ONECHAR op
+        //   to a string op.
         if (fModeFlags & UREGEX_CASE_INSENSITIVE) {
             op     = URX_BUILD(URX_STRING_I, fStringOpStart);
         } else {
@@ -1460,7 +1475,7 @@ void RegexCompile::literalChar(UChar32 c)  {
         op         = URX_BUILD(URX_STRING_LEN, 0);
         fRXPat->fCompiledPat->addElement(op, *fStatus);
     }
-
+    
     // The pattern contains a URX_SRING / URX_STRING_LEN.  Update the
     //  string length to reflect the new char we just added to the string.
     stringLen  = fRXPat->fLiteralText.length() - fStringOpStart;
diff --git a/icu4c/source/test/testdata/regextst.txt b/icu4c/source/test/testdata/regextst.txt
index a0ee9ee0e8..cf08f6be9f 100644
--- a/icu4c/source/test/testdata/regextst.txt
+++ b/icu4c/source/test/testdata/regextst.txt
@@ -338,6 +338,17 @@
 "ab\x{101234}c"                    "<0>ab\U00101234c</0>"
 "abα"                            "<0>abα</0>"
 
+
+#
+#  \u Surrogate Pairs
+#
+"\ud800\udc00"                    "<0>\U00010000</0>"
+"\ud800\udc00*"                   "<0>\U00010000\U00010000\U00010000</0>\U00010001"
+"\ud800\ud800\udc00"              "<0>\ud800\U00010000</0>\U00010000\U00010000\U00010001"
+"(\ud800)(\udc00)"                "\u00010000"
+
+
+
 #
 #  Random debugging, Temporary
 #