Index: include/lld/ReaderWriter/ELFLinkingContext.h
===================================================================
--- include/lld/ReaderWriter/ELFLinkingContext.h
+++ include/lld/ReaderWriter/ELFLinkingContext.h
@@ -262,8 +262,8 @@
 
   void setCreateSeparateROSegment() { _mergeRODataToTextSegment = false; }
 
-  bool hasCoalescedWeakPair(StringRef name) const {
-    return _weakCoalescedSymbols.count(name) != 0;
+  bool hasCoalescedSharedLibPair(StringRef name) const {
+    return _sharedLibCoalescedSymbols.count(name) != 0;
   }
 
 private:
@@ -300,7 +300,7 @@
   StringRefVector _rpathList;
   StringRefVector _rpathLinkList;
   std::map<std::string, uint64_t> _absoluteSymbols;
-  llvm::StringSet<> _weakCoalescedSymbols;
+  llvm::StringSet<> _sharedLibCoalescedSymbols;
 };
 } // end namespace lld
 
Index: lib/ReaderWriter/ELF/ELFLinkingContext.cpp
===================================================================
--- lib/ReaderWriter/ELF/ELFLinkingContext.cpp
+++ lib/ReaderWriter/ELF/ELFLinkingContext.cpp
@@ -241,11 +241,6 @@
   return std::move(undefinedSymFile);
 }
 
-static bool isSharedWeakAtom(const UndefinedAtom *ua) {
-  return ua->canBeNull() != UndefinedAtom::canBeNullNever &&
-         isa<SharedLibraryFile>(ua->file());
-}
-
 void ELFLinkingContext::notifySymbolTableCoalesce(const Atom *existingAtom,
                                                   const Atom *newAtom,
                                                   bool &useNew) {
@@ -259,11 +254,12 @@
     ua = dyn_cast<UndefinedAtom>(existingAtom);
   }
 
-  if (da && ua && da->scope() == Atom::scopeGlobal && isSharedWeakAtom(ua))
-    // If strong defined atom coalesces away weak atom declared
-    // in the shared object the strong atom needs to be dynamicaly exported.
+  if (da && ua && da->scope() == Atom::scopeGlobal &&
+      isa<SharedLibraryFile>(ua->file()))
+    // If strong defined atom coalesces away an atom declared
+    // in the shared object the strong atom needs to be dynamically exported.
     // Save its name.
-    _weakCoalescedSymbols.insert(ua->name());
+    _sharedLibCoalescedSymbols.insert(ua->name());
 }
 
 } // end namespace lld
Index: lib/ReaderWriter/ELF/OutputELFWriter.h
===================================================================
--- lib/ReaderWriter/ELF/OutputELFWriter.h
+++ lib/ReaderWriter/ELF/OutputELFWriter.h
@@ -183,7 +183,7 @@
       for (const auto &atom : section->atoms()) {
         const DefinedAtom *da = dyn_cast<const DefinedAtom>(atom->_atom);
         if (da && (da->dynamicExport() == DefinedAtom::dynamicExportAlways ||
-                   _context.hasCoalescedWeakPair(da->name())))
+                   _context.hasCoalescedSharedLibPair(da->name())))
           _dynamicSymbolTable->addSymbol(atom->_atom, section->ordinal(),
                                          atom->_virtualAddr, atom);
       }
Index: test/elf/Inputs/undef2-so.o.yaml
===================================================================
--- /dev/null
+++ test/elf/Inputs/undef2-so.o.yaml
@@ -0,0 +1,50 @@
+---
+FileHeader:      
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:        
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000001
+    Content:         554889E5488B05000000008B005DC3
+  - Name:            .rela.text
+    Type:            SHT_RELA
+    Link:            .symtab
+    AddressAlign:    0x0000000000000008
+    Info:            .text
+    Relocations:     
+      - Offset:          0x0000000000000007
+        Symbol:          myexportedsymbol
+        Type:            R_X86_64_GOTPCREL
+        Addend:          -4
+  - Name:            .data
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x0000000000000001
+    Content:         ''
+  - Name:            .bss
+    Type:            SHT_NOBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x0000000000000001
+    Content:         ''
+Symbols:         
+  Local:           
+    - Name:            .text
+      Type:            STT_SECTION
+      Section:         .text
+    - Name:            .data
+      Type:            STT_SECTION
+      Section:         .data
+    - Name:            .bss
+      Type:            STT_SECTION
+      Section:         .bss
+  Global:          
+    - Name:            func
+      Type:            STT_FUNC
+      Section:         .text
+      Size:            0x000000000000000F
+    - Name:            _GLOBAL_OFFSET_TABLE_
+    - Name:            myexportedsymbol
Index: test/elf/undef-from-dso-to-main.test
===================================================================
--- /dev/null
+++ test/elf/undef-from-dso-to-main.test
@@ -0,0 +1,52 @@
+# Tests that a reference from a DSO to a regular object
+# forces the final executable to export the symbol.
+
+#RUN: yaml2obj -format=elf %p/Inputs/undef2-so.o.yaml -o=%t.o.so
+#RUN: lld -flavor gnu  -target x86_64 -shared %t.o.so -o %T/libundef2.so
+#RUN: yaml2obj -format=elf %s -o=%t.o
+#RUN: lld -flavor gnu  -target x86_64 %t.o -L%T -lundef2 -o %t1
+#RUN: llvm-readobj -dyn-symbols %t1 | FileCheck -check-prefix CHECKSYMS %s
+
+---
+FileHeader:      
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:        
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000001
+    Content:         C3
+  - Name:            .data
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x0000000000000001
+    Content:         ''
+  - Name:            .bss
+    Type:            SHT_NOBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x0000000000000004
+    Content:         '002E7379'
+Symbols:         
+  Local:           
+    - Name:            .text
+      Type:            STT_SECTION
+      Section:         .text
+    - Name:            .data
+      Type:            STT_SECTION
+      Section:         .data
+    - Name:            .bss
+      Type:            STT_SECTION
+      Section:         .bss
+  Global:          
+    - Name:            myexportedsymbol
+      Type:            STT_OBJECT
+      Section:         .bss
+      Size:            0x0000000000000004
+    - Name:            _start
+      Section:         .text
+      Size:            0x0000000000000001
+
+#CHECKSYMS: myexportedsymbol