make REPL completions robust against expanduser throwing (#47058)

(cherry picked from commit 7beeaf7)

Author: KristofferC

stdlib/REPL/src/REPLCompletions.jl

@@ -306,7 +306,12 @@ function complete_path(path::AbstractString, pos::Int; use_envpath=false, shell_
 end
 
 function complete_expanduser(path::AbstractString, r)
-    expanded = expanduser(path)
+    expanded =
+        try expanduser(path)
+        catch e
+            e isa ArgumentError || rethrow()
+            path
+        end
     return Completion[PathCompletion(expanded)], r, path != expanded
 end
 

stdlib/REPL/test/replcompletions.jl

@@ -716,6 +716,9 @@ let s, c, r
             s = "\"~"
             @test "tmpfoobar/" in c
             c,r = test_complete(s)
+            s = "\"~user"
+            c, r = test_complete(s)
+            @test isempty(c)
             rm(dir)
         end
     end