Index: lldb/source/Utility/TildeExpressionResolver.cpp
===================================================================
--- lldb/source/Utility/TildeExpressionResolver.cpp
+++ lldb/source/Utility/TildeExpressionResolver.cpp
@@ -75,9 +75,8 @@
 
 bool TildeExpressionResolver::ResolveFullPath(
     StringRef Expr, llvm::SmallVectorImpl<char> &Output) {
-  Output.clear();
   if (!Expr.startswith("~")) {
-    Output.append(Expr.begin(), Expr.end());
+    Output.assign(Expr.begin(), Expr.end());
     return false;
   }
 
@@ -85,8 +84,10 @@
   StringRef Left =
       Expr.take_until([](char c) { return path::is_separator(c); });
 
-  if (!ResolveExact(Left, Output))
+  if (!ResolveExact(Left, Output)) {
+    Output.assign(Expr.begin(), Expr.end());
     return false;
+  }
 
   Output.append(Expr.begin() + Left.size(), Expr.end());
   return true;