diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index bf9d357..5afd9a0 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,27 @@
+2012-06-18  Mark Lam  <mark.lam@apple.com>
+
+        Changed JSC to always record line number information so that error.stack
+        and window.onerror() can report proper line numbers.
+        https://bugs.webkit.org/show_bug.cgi?id=89410
+
+        Reviewed by Geoffrey Garen.
+
+        * bytecode/CodeBlock.cpp:
+        (JSC::CodeBlock::CodeBlock):
+        (JSC::CodeBlock::lineNumberForBytecodeOffset):
+        (JSC::CodeBlock::shrinkToFit): m_lineInfo is now available unconditionally.
+
+        * bytecode/CodeBlock.h:
+        (JSC::CodeBlock::addLineInfo):
+        (JSC::CodeBlock::hasLineInfo): Unused.  Now removed.
+        (JSC::CodeBlock::needsCallReturnIndices):
+        (CodeBlock):
+        (RareData):  Hoisted m_lineInfo out of m_rareData.  m_lineInfo is now
+        filled in unconditionally.
+
+        * bytecompiler/BytecodeGenerator.h:
+        (JSC::BytecodeGenerator::addLineInfo):
+
 2012-06-18  Andy Estes  <aestes@apple.com>
 
         Fix r120663, which didn't land the change that was reviewed.
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
index 5f4006c..60596d1 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -1600,6 +1600,7 @@
     , m_forcedOSRExitCounter(0)
     , m_optimizationDelayCounter(0)
     , m_reoptimizationRetryCounter(0)
+    , m_lineInfo(other.m_lineInfo)
 #if ENABLE(JIT)
     , m_canCompileWithDFGState(DFG::CapabilityLevelNotSet)
 #endif
@@ -1607,7 +1608,7 @@
     setNumParameters(other.numParameters());
     optimizeAfterWarmUp();
     jitAfterWarmUp();
-    
+
     if (other.m_rareData) {
         createRareDataIfNecessary();
         
@@ -1618,7 +1619,6 @@
         m_rareData->m_characterSwitchJumpTables = other.m_rareData->m_characterSwitchJumpTables;
         m_rareData->m_stringSwitchJumpTables = other.m_rareData->m_stringSwitchJumpTables;
         m_rareData->m_expressionInfo = other.m_rareData->m_expressionInfo;
-        m_rareData->m_lineInfo = other.m_rareData->m_lineInfo;
     }
 }
 
@@ -2163,10 +2163,7 @@
 {
     ASSERT(bytecodeOffset < instructions().size());
 
-    if (!m_rareData)
-        return m_ownerExecutable->source().firstLine();
-
-    Vector<LineInfo>& lineInfo = m_rareData->m_lineInfo;
+    Vector<LineInfo>& lineInfo = m_lineInfo;
 
     int low = 0;
     int high = lineInfo.size();
@@ -2291,6 +2288,7 @@
         m_constantRegisters.shrinkToFit();
     } // else don't shrink these, because we would have already pointed pointers into these tables.
 
+    m_lineInfo.shrinkToFit();
     if (m_rareData) {
         m_rareData->m_exceptionHandlers.shrinkToFit();
         m_rareData->m_regexps.shrinkToFit();
@@ -2298,7 +2296,6 @@
         m_rareData->m_characterSwitchJumpTables.shrinkToFit();
         m_rareData->m_stringSwitchJumpTables.shrinkToFit();
         m_rareData->m_expressionInfo.shrinkToFit();
-        m_rareData->m_lineInfo.shrinkToFit();
 #if ENABLE(JIT)
         m_rareData->m_callReturnIndexVector.shrinkToFit();
 #endif
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.h b/Source/JavaScriptCore/bytecode/CodeBlock.h
index aa724fc..67b377e 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.h
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.h
@@ -711,8 +711,7 @@
 
         void addLineInfo(unsigned bytecodeOffset, int lineNo)
         {
-            createRareDataIfNecessary();
-            Vector<LineInfo>& lineInfo = m_rareData->m_lineInfo;
+            Vector<LineInfo>& lineInfo = m_lineInfo;
             if (!lineInfo.size() || lineInfo.last().lineNumber != lineNo) {
                 LineInfo info = { bytecodeOffset, lineNo };
                 lineInfo.append(info);
@@ -720,13 +719,12 @@
         }
 
         bool hasExpressionInfo() { return m_rareData && m_rareData->m_expressionInfo.size(); }
-        bool hasLineInfo() { return m_rareData && m_rareData->m_lineInfo.size(); }
         //  We only generate exception handling info if the user is debugging
         // (and may want line number info), or if the function contains exception handler.
         bool needsCallReturnIndices()
         {
-            return m_rareData &&
-                (m_rareData->m_expressionInfo.size() || m_rareData->m_lineInfo.size() || m_rareData->m_exceptionHandlers.size());
+            return true || (m_rareData
+                && (m_rareData->m_expressionInfo.size() || m_rareData->m_exceptionHandlers.size()));
         }
 
 #if ENABLE(JIT)
@@ -1311,7 +1309,9 @@
         uint32_t m_forcedOSRExitCounter;
         uint16_t m_optimizationDelayCounter;
         uint16_t m_reoptimizationRetryCounter;
-        
+
+        Vector<LineInfo> m_lineInfo;
+
         struct RareData {
            WTF_MAKE_FAST_ALLOCATED;
         public:
@@ -1333,7 +1333,6 @@
             // Expression info - present if debugging.
             Vector<ExpressionRangeInfo> m_expressionInfo;
             // Line info - present if profiling or debugging.
-            Vector<LineInfo> m_lineInfo;
 #if ENABLE(JIT)
             Vector<CallReturnOffsetToBytecodeOffset> m_callReturnIndexVector;
 #endif
diff --git a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
index 8c3fc7b..8b1d1d7 100644
--- a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
+++ b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -616,10 +616,7 @@
 
         void addLineInfo(unsigned lineNo)
         {
-#if !ENABLE(OPCODE_SAMPLING)
-            if (m_shouldEmitRichSourceInfo)
-#endif
-                m_codeBlock->addLineInfo(instructions().size(), lineNo);
+            m_codeBlock->addLineInfo(instructions().size(), lineNo);
         }
 
         RegisterID* emitInitLazyRegister(RegisterID*);