Index: ELF/InputFiles.cpp
===================================================================
--- ELF/InputFiles.cpp
+++ ELF/InputFiles.cpp
@@ -178,6 +178,13 @@
   if (Config->Optimize == 0)
     return false;
 
+  // In case of relocatable object generation we do not update any relocation
+  // addends, but as a result of the merging section's size might change
+  // and so we get a relocation points to out of the section border.
+  // To prevent this do not merge sections.
+  if (Config->Relocatable)
+    return false;
+
   // A mergeable section with size 0 is useless because they don't have
   // any data to merge. A mergeable string section with size 0 can be
   // argued as invalid because it doesn't end with a null character.
Index: test/ELF/merge.s
===================================================================
--- test/ELF/merge.s
+++ test/ELF/merge.s
@@ -5,6 +5,9 @@
 // RUN: llvm-readobj -s -section-data -t %t | FileCheck %s
 // RUN: llvm-objdump -d %t | FileCheck --check-prefix=DISASM %s
 
+// RUN: ld.lld %t.o %t2.o -r -o %t-rel
+// RUN: llvm-readobj -s -section-data %t-rel | FileCheck --check-prefix=REL %s
+
         .section        .mysec,"aM",@progbits,4
         .align  4
         .global foo
@@ -109,3 +112,21 @@
 //  From the other file:  movl .mysec, %eax
 // addr(0x42) = 65828
 // DISASM-NEXT:   movl    65828, %eax
+
+// REL:      Name: .mysec
+// REL-NEXT: Type: SHT_PROGBITS
+// REL-NEXT:    Flags [
+// REL-NEXT:      SHF_ALLOC
+// REL-NEXT:      SHF_MERGE
+// REL-NEXT:    ]
+// REL-NEXT:    Address: 0x0
+// REL-NEXT:    Offset: 0x40
+// REL-NEXT:    Size: 20
+// REL-NEXT:    Link: 0
+// REL-NEXT:    Info: 0
+// REL-NEXT:    AddressAlignment: 4
+// REL-NEXT:    EntrySize: 0
+// REL-NEXT:    SectionData (
+// REL-NEXT:      0000: 10000000 42000000 42000000 42000000
+// REL-NEXT:      0010: 42000000
+// REL-NEXT:    )