### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: compiler/org/eclipse/jdt/internal/compiler/flow/LoopingFlowContext.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/flow/LoopingFlowContext.java,v
retrieving revision 1.56
diff -u -r1.56 LoopingFlowContext.java
--- compiler/org/eclipse/jdt/internal/compiler/flow/LoopingFlowContext.java	8 Mar 2011 16:46:01 -0000	1.56
+++ compiler/org/eclipse/jdt/internal/compiler/flow/LoopingFlowContext.java	11 Apr 2011 15:22:37 -0000
@@ -548,7 +548,10 @@
 		case CAN_ONLY_NULL | IN_ASSIGNMENT:
 		case CAN_ONLY_NULL | IN_INSTANCEOF:
 			if (flowInfo.isPotentiallyNonNull(local)
-					|| flowInfo.isPotentiallyUnknown(local)) {
+					|| flowInfo.isPotentiallyUnknown(local)
+					|| flowInfo.isProtectedNonNull(local)) {
+				// if variable is not null, we are not interested in recording null reference for deferred checks.
+				// This is because CAN_ONLY_NULL means we're only interested in cases when variable can be null.
 				return;
 			}
 			if (flowInfo.isDefinitelyNull(local)) {
#P org.eclipse.jdt.core.tests.compiler
Index: src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java,v
retrieving revision 1.118
diff -u -r1.118 NullReferenceTest.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java	9 Mar 2011 13:57:50 -0000	1.118
+++ src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java	11 Apr 2011 15:22:39 -0000
@@ -14530,4 +14530,52 @@
 		"Dead code\n" + 
 		"----------\n");
 }
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=342300
+public void testBug342300() throws Exception {
+	if (this.complianceLevel >= ClassFileConstants.JDK1_5) {
+		this.runConformTest(
+			new String[] {
+				"X.java",
+				"public class X {\n" + 
+				"	public static void initPattern(String p, Character escapeChar) {\n" + 
+				"		int len = p.length();\n" +
+				"		for (int i = 0; i < len; i++) {\n" +
+				"			char c = p.charAt(i);\n" +
+				"			if (escapeChar != null && escapeChar == c) {\n" +	// quiet
+				"				c = p.charAt(++i);\n" +
+				"			}\n" + 
+				"	    }\n" + 
+				"	}\n" + 
+				"}",
+			},
+			"");
+	}
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=342300
+// To make sure only the redundant null check is given and not a potential NPE
+public void testBug342300b() throws Exception {
+	if (this.complianceLevel >= ClassFileConstants.JDK1_5) {
+		this.runNegativeTest(
+			new String[] {
+				"X.java",
+				"public class X {\n" + 
+				"	public static void initPattern(String p, Character escapeChar) {\n" + 
+				"		int len = p.length();\n" +
+				"		for (int i = 0; i < len; i++) {\n" +
+				"			char c = p.charAt(i);\n" +
+				"			if (escapeChar != null && escapeChar != null) {\n" +	// look here
+				"				c = p.charAt(++i);\n" +
+				"			}\n" + 
+				"	    }\n" + 
+				"	}\n" + 
+				"}",
+			},
+			"----------\n" + 
+			"1. ERROR in X.java (at line 6)\n" + 
+			"	if (escapeChar != null && escapeChar != null) {\n" + 
+			"	                          ^^^^^^^^^^\n" + 
+			"Redundant null check: The variable escapeChar cannot be null at this location\n" + 
+			"----------\n");
+	}
+}
 }
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