For PR1050:
Convert asserts into error messages.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32607 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Archive/Archive.cpp b/lib/Bytecode/Archive/Archive.cpp
index a661a4e..3bbc49d 100644
--- a/lib/Bytecode/Archive/Archive.cpp
+++ b/lib/Bytecode/Archive/Archive.cpp
@@ -62,7 +62,12 @@
 // different file, presumably as an update to the member. It also makes sure
 // the flags are reset correctly.
 bool ArchiveMember::replaceWith(const sys::Path& newFile, std::string* ErrMsg) {
-  assert(newFile.exists() && "Can't replace with a non-existent file");
+  if (!newFile.exists()) {
+    if (ErrMsg) 
+      *ErrMsg = "Can not replace an archive member with a non-existent file";
+    return true;
+  }
+
   data = 0;
   path = newFile;