### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionScanner.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionScanner.java,v
retrieving revision 1.70
diff -u -r1.70 CompletionScanner.java
--- codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionScanner.java	6 Oct 2009 01:00:37 -0000	1.70
+++ codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionScanner.java	7 Apr 2010 19:40:13 -0000
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2009 IBM Corporation and others.
+ * Copyright (c) 2000, 2010 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -21,6 +21,7 @@
  *  n  means completion behind the n-th character
  */
 import org.eclipse.jdt.core.compiler.*;
+import org.eclipse.jdt.internal.compiler.classfmt.ClassFileConstants;
 import org.eclipse.jdt.internal.compiler.parser.Scanner;
 import org.eclipse.jdt.internal.compiler.parser.ScannerHelper;
 
@@ -791,7 +792,39 @@
 					throw new InvalidInputException("Ctrl-Z"); //$NON-NLS-1$
 
 				default :
-					if (ScannerHelper.isJavaIdentifierStart(this.currentCharacter))
+					char c = this.currentCharacter;
+					if (c < ScannerHelper.MAX_OBVIOUS) {
+						if ((ScannerHelper.OBVIOUS_IDENT_CHAR_NATURES[c] & ScannerHelper.C_IDENT_START) != 0) {
+							return scanIdentifierOrKeyword();
+						} else if ((ScannerHelper.OBVIOUS_IDENT_CHAR_NATURES[c] & ScannerHelper.C_DIGIT) != 0) {
+								return scanNumber(false);
+						} else {
+							return TokenNameERROR;
+						}
+					}
+					boolean isJavaIdStart;
+					if (c >= HIGH_SURROGATE_MIN_VALUE && c <= HIGH_SURROGATE_MAX_VALUE) {
+						if (this.complianceLevel < ClassFileConstants.JDK1_5) {
+							throw new InvalidInputException(INVALID_UNICODE_ESCAPE);
+						}
+						// Unicode 4 detection
+						char low = (char) getNextChar();
+						if (low < LOW_SURROGATE_MIN_VALUE || low > LOW_SURROGATE_MAX_VALUE) {
+							// illegal low surrogate
+							throw new InvalidInputException(INVALID_LOW_SURROGATE);
+						}
+						isJavaIdStart = ScannerHelper.isJavaIdentifierStart(c, low);
+					}
+					else if (c >= LOW_SURROGATE_MIN_VALUE && c <= LOW_SURROGATE_MAX_VALUE) {
+						if (this.complianceLevel < ClassFileConstants.JDK1_5) {
+							throw new InvalidInputException(INVALID_UNICODE_ESCAPE);
+						}
+						throw new InvalidInputException(INVALID_HIGH_SURROGATE);
+					} else {
+						// optimized case already checked
+						isJavaIdStart = Character.isJavaIdentifierStart(c);
+					}
+					if (isJavaIdStart)
 						return scanIdentifierOrKeyword();
 					if (ScannerHelper.isDigit(this.currentCharacter)) {
 						return scanNumber(false);
#P org.eclipse.jdt.core.tests.model
Index: src/org/eclipse/jdt/core/tests/model/CompletionTests_1_5.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests_1_5.java,v
retrieving revision 1.118
diff -u -r1.118 CompletionTests_1_5.java
--- src/org/eclipse/jdt/core/tests/model/CompletionTests_1_5.java	9 Jul 2009 10:47:24 -0000	1.118
+++ src/org/eclipse/jdt/core/tests/model/CompletionTests_1_5.java	7 Apr 2010 19:40:16 -0000
@@ -13790,5 +13790,29 @@
 					(R_DEFAULT + R_RESOLVED + R_INTERESTING + R_CASE + R_UNQUALIFIED + R_EXACT_EXPECTED_TYPE + R_NON_RESTRICTED) + "}",
 			requestor.getResults());	
 }
+//https://bugs.eclipse.org/bugs/show_bug.cgi?id=307486
+public void testLabel7() throws JavaModelException {
+	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies[0] = getWorkingCopy(
+		"/Completion/src/label/Test.java",
+		"package label;"+
+		"public class Test {\n" +
+		"  void foo() {\n" +
+		"    \ud842\udf9fabc :\n" +
+		"    while (true) {\n" + 
+		"        break \ud842\udf9fabc;\n" + 
+		"    }\n" + 
+		"  }\n" +
+		"}\n");
 
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "break";
+	int cursorLocation = str.lastIndexOf(completeBehind) + completeBehind.length() + 1;
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+
+	assertResults(
+			"\ud842\udf9fabc[LABEL_REF]{\ud842\udf9fabc, null, null, \ud842\udf9fabc, null, " + (R_DEFAULT + R_RESOLVED + R_INTERESTING + R_CASE + R_NON_RESTRICTED) + "}",
+			requestor.getResults());
+}
 }