### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: compiler/org/eclipse/jdt/internal/compiler/flow/NullInfoRegistry.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/flow/NullInfoRegistry.java,v
retrieving revision 1.10
diff -u -r1.10 NullInfoRegistry.java
--- compiler/org/eclipse/jdt/internal/compiler/flow/NullInfoRegistry.java	7 Mar 2009 01:08:10 -0000	1.10
+++ compiler/org/eclipse/jdt/internal/compiler/flow/NullInfoRegistry.java	20 Jul 2010 16:40:57 -0000
@@ -319,7 +319,7 @@
 			// prot. non null
 		& ((a2 = this.nullBit2) | (a4 = this.nullBit4));
 			// null or unknown
-	m2 = s1 & (s2 = this.nullBit2) & (s3 ^ s4)
+	m2 = s1 & (s2 = this.nullBit2) & (s3 ^ s4) // TODO(stephan): potential typo: should this be "s2 = source.nullBit2"???
 			// prot. null
 		& ((a3 = this.nullBit3) | a4);
 			// non null or unknown
@@ -336,6 +336,18 @@
 		source.nullBit2 &= (nm1 = ~m1) & ((nm2 = ~m2) | a4);
 		source.nullBit3 &= (nm1 | a2) & nm2;
 		source.nullBit4 &= nm1 & nm2;
+		// any variable that is (pot n, pot nn, pot un) at end of try (as captured by *this* NullInfoRegistry)
+		// has the same uncertainty also for the mitigated case (function result)
+		// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=320170 -  [compiler] [null] Whitebox issues in null analysis
+		// and org.eclipse.jdt.core.tests.compiler.regression.NullReferenceTest.test0536_try_finally()
+		long x = ~this.nullBit1 & a2 & a3 & a4; // x is set for all variable ids that have state 0111 (pot n, pot nn, pot un)
+		if (x != 0) {
+			// restore state 0111 for all variable ids in x:
+			source.nullBit1 &= ~x;
+			source.nullBit2 |= x;
+			source.nullBit3 |= x;
+			source.nullBit4 |= x;
+		}
 	}
 	if (this.extra != null && source.extra != null) {
 		int length = this.extra[2].length, sourceLength = source.extra[0].length;
Index: compiler/org/eclipse/jdt/internal/compiler/flow/UnconditionalFlowInfo.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/flow/UnconditionalFlowInfo.java,v
retrieving revision 1.65
diff -u -r1.65 UnconditionalFlowInfo.java
--- compiler/org/eclipse/jdt/internal/compiler/flow/UnconditionalFlowInfo.java	24 Feb 2010 20:12:40 -0000	1.65
+++ compiler/org/eclipse/jdt/internal/compiler/flow/UnconditionalFlowInfo.java	20 Jul 2010 16:40:59 -0000
@@ -63,6 +63,7 @@
 		0100	pot. null
 		0101	pot. n & pot. un
 		0110	pot. n & pot. nn
+		0111    pot. n & pot. nn & pot. un
 		1001	def. unknown
 		1010	def. non null
 		1011	pot. nn & prot. nn
#P org.eclipse.jdt.core.tests.compiler
Index: src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceImplTests.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceImplTests.java,v
retrieving revision 1.9
diff -u -r1.9 NullReferenceImplTests.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceImplTests.java	28 Apr 2009 17:17:38 -0000	1.9
+++ src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceImplTests.java	20 Jul 2010 16:41:03 -0000
@@ -96,7 +96,7 @@
 			011001
 			011010
 			011011
-			011100
+			011100  pot. n & pot. nn & pot. un
 			011101
 			011110
 			011111
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 1.95
diff -u -r1.95 NullReferenceTest.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java	16 Mar 2010 14:36:08 -0000	1.95
+++ src/org/eclipse/jdt/core/tests/compiler/regression/NullReferenceTest.java	20 Jul 2010 16:41:17 -0000
@@ -5484,6 +5484,35 @@
 			"");
 }
 
+// null analysis -- try/finally
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=320170 -  [compiler] [null] Whitebox issues in null analysis
+// trigger nullbits 0111 (pot n|nn|un), don't let "definitely unknown" override previous information
+public void test0536_try_finally() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X {\n" +
+			" X bar () { return null; }\n" +
+			" void foo() {\n" +
+			"   X x = new X();\n" +
+			"   try {\n" +
+			"     x = null;\n" +
+			"     x = new X();\n" +  // if this throws an exception finally finds x==null
+			"     x = bar();\n" +
+			"   } finally {\n" +
+			"     x.toString();\n" + // complain
+			"   }\n" +
+			" }\n" +
+			"}\n"},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 10)\n" + 
+		"	x.toString();\n" + 
+		"	^\n" + 
+		"Potential null pointer access: The variable x may be null at this location\n" + 
+		"----------\n",
+	    JavacTestOptions.Excuse.EclipseWarningConfiguredAsError);
+}
+
 // null analysis -- try/catch
 public void test0550_try_catch() {
 	this.runConformTest(