--- mfbt/SHA1.h~
+++ mfbt/SHA1.h
@@ -27,6 +27,11 @@
 #include "mozilla/StandardInteger.h"
 #include "mozilla/Types.h"
 
+#if !defined(__clang__) && defined(__GNUC__) && __GNUC_MINOR__ <= 3
+/* c++/36107: mark SHA1Sum constructor as weak manually */
+__asm__(".weak _ZN7mozilla7SHA1SumC1Ev");
+#endif
+
 namespace mozilla {
 class SHA1Sum {
   union {
@@ -39,7 +43,12 @@ class SHA1Sum {
 
 public:
   static const unsigned int HashSize = 20;
+#if !defined(__clang__) && defined(__GNUC__) && __GNUC_MINOR__ <= 3
+  /* c++/36107: gcc42 fails to remove *INTERNAL* from produced asm */
+  MOZ_IMPORT_API() SHA1Sum();
+#else
   MFBT_API() SHA1Sum();
+#endif
   MFBT_API(void) update(const void* dataIn, uint32_t len);
   MFBT_API(void) finish(uint8_t hashout[20]);
 };