diff --git a/mail/thunderbird/files/patch-bug784631 b/mail/thunderbird/files/patch-bug784631
new file mode 100644
index 000000000000..6378663b9b70
--- /dev/null
+++ b/mail/thunderbird/files/patch-bug784631
@@ -0,0 +1,52 @@
+commit 66b3921
+Author: Terrence Cole <terrence@mozilla.com>
+Date:   Tue Sep 11 12:31:04 2012 -0700
+
+    Bug 784631 - Fix some clang build errors in SpiderMonkey; r=Waldo f=espindola
+    
+    Computed gotos are not in the C++ standard: clang and gcc differ on semantics.
+---
+ js/src/jsinterp.cpp | 3 ++-
+ js/src/jsutil.h     | 8 ++++----
+ 2 files changed, 6 insertions(+), 5 deletions(-)
+
+diff --git js/src/jsinterp.cpp js/src/jsinterp.cpp
+index 0094c72..27a64a7 100644
+--- mozilla/js/src/jsinterp.cpp
++++ mozilla/js/src/jsinterp.cpp
+@@ -1231,6 +1231,7 @@ js::Interpret(JSContext *cx, StackFrame *entryFrame, InterpMode interpMode)
+     RootedPropertyName rootName0(cx);
+     RootedId rootId0(cx);
+     RootedShape rootShape0(cx);
++    DebugOnly<uint32_t> blockDepth;
+ 
+     if (!entryFrame)
+         entryFrame = regs.fp();
+@@ -3650,7 +3651,7 @@ BEGIN_CASE(JSOP_LEAVEBLOCK)
+ BEGIN_CASE(JSOP_LEAVEFORLETIN)
+ BEGIN_CASE(JSOP_LEAVEBLOCKEXPR)
+ {
+-    DebugOnly<uint32_t> blockDepth = regs.fp()->blockChain().stackDepth();
++    blockDepth = regs.fp()->blockChain().stackDepth();
+ 
+     regs.fp()->popBlock(cx);
+ 
+diff --git js/src/jsutil.h js/src/jsutil.h
+index 8838b6f..016a877 100644
+--- mozilla/js/src/jsutil.h
++++ mozilla/js/src/jsutil.h
+@@ -432,10 +432,10 @@ typedef size_t jsbitmap;
+ #if defined(__clang__)
+ # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \
+     JS_BEGIN_MACRO                                                            \
+-        _Pragma("clang diagnostic push")                                      \
+-        _Pragma("clang diagnostic ignored \"-Wunused-value\"")                \
+-        expr;                                                                 \
+-        _Pragma("clang diagnostic pop")                                       \
++        _Pragma("(clang diagnostic push)")                                    \
++        _Pragma("(clang diagnostic ignored \"-Wunused-value\")")              \
++        {expr;}                                                               \
++        _Pragma("(clang diagnostic pop)")                                     \
+     JS_END_MACRO
+ #elif (__GNUC__ >= 5) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+ # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \
diff --git a/www/firefox/files/patch-bug784631 b/www/firefox/files/patch-bug784631
new file mode 100644
index 000000000000..2c8a1560b877
--- /dev/null
+++ b/www/firefox/files/patch-bug784631
@@ -0,0 +1,52 @@
+commit 66b3921
+Author: Terrence Cole <terrence@mozilla.com>
+Date:   Tue Sep 11 12:31:04 2012 -0700
+
+    Bug 784631 - Fix some clang build errors in SpiderMonkey; r=Waldo f=espindola
+    
+    Computed gotos are not in the C++ standard: clang and gcc differ on semantics.
+---
+ js/src/jsinterp.cpp | 3 ++-
+ js/src/jsutil.h     | 8 ++++----
+ 2 files changed, 6 insertions(+), 5 deletions(-)
+
+diff --git js/src/jsinterp.cpp js/src/jsinterp.cpp
+index 0094c72..27a64a7 100644
+--- js/src/jsinterp.cpp
++++ js/src/jsinterp.cpp
+@@ -1231,6 +1231,7 @@ js::Interpret(JSContext *cx, StackFrame *entryFrame, InterpMode interpMode)
+     RootedPropertyName rootName0(cx);
+     RootedId rootId0(cx);
+     RootedShape rootShape0(cx);
++    DebugOnly<uint32_t> blockDepth;
+ 
+     if (!entryFrame)
+         entryFrame = regs.fp();
+@@ -3650,7 +3651,7 @@ BEGIN_CASE(JSOP_LEAVEBLOCK)
+ BEGIN_CASE(JSOP_LEAVEFORLETIN)
+ BEGIN_CASE(JSOP_LEAVEBLOCKEXPR)
+ {
+-    DebugOnly<uint32_t> blockDepth = regs.fp()->blockChain().stackDepth();
++    blockDepth = regs.fp()->blockChain().stackDepth();
+ 
+     regs.fp()->popBlock(cx);
+ 
+diff --git js/src/jsutil.h js/src/jsutil.h
+index 8838b6f..016a877 100644
+--- js/src/jsutil.h
++++ js/src/jsutil.h
+@@ -432,10 +432,10 @@ typedef size_t jsbitmap;
+ #if defined(__clang__)
+ # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \
+     JS_BEGIN_MACRO                                                            \
+-        _Pragma("clang diagnostic push")                                      \
+-        _Pragma("clang diagnostic ignored \"-Wunused-value\"")                \
+-        expr;                                                                 \
+-        _Pragma("clang diagnostic pop")                                       \
++        _Pragma("(clang diagnostic push)")                                    \
++        _Pragma("(clang diagnostic ignored \"-Wunused-value\")")              \
++        {expr;}                                                               \
++        _Pragma("(clang diagnostic pop)")                                     \
+     JS_END_MACRO
+ #elif (__GNUC__ >= 5) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+ # define JS_SILENCE_UNUSED_VALUE_IN_EXPR(expr)                                \