Fix a few cases of REPL completion crash (#43541)

stdlib/REPL/src/REPLCompletions.jl

@@ -466,11 +466,22 @@ function get_type(sym::Expr, fn::Module)
     val, found = try_get_type(sym, fn)
     found && return val, found
     # https://github.com/JuliaLang/julia/issues/27184
-    if isexpr(sym, :macrocall)
+    newsym = if isexpr(sym, :macrocall)
         _, found = get_type(first(sym.args), fn)
         found || return Any, false
+        try
+            Meta.lower(fn, sym)
+        catch e
+            e isa LoadError && return Any, false
+            # If e is not a LoadError then Meta.lower crashed in an unexpected way.
+            # Since this is not a specific to the user code but an internal error,
+            # rethrow the error to allow reporting it.
+            rethrow()
+        end
+    else
+        Meta.lower(fn, sym)
     end
-    return try_get_type(Meta.lower(fn, sym), fn)
+    return try_get_type(newsym, fn)
 end
 
 function get_type(sym, fn::Module)
@@ -611,6 +622,21 @@ function afterusing(string::String, startpos::Int)
     return occursin(r"^\b(using|import)\s*((\w+[.])*\w+\s*,\s*)*$", str[fr:end])
 end
 
+function close_path_completion(str, startpos, r, paths, pos)
+    length(paths) == 1 || return false  # Only close if there's a single choice...
+    _path = str[startpos:prevind(str, first(r))] * (paths[1]::PathCompletion).path
+    path = expanduser(replace(_path, r"\\ " => " "))
+    # ...except if it's a directory...
+    try
+        isdir(path)
+    catch e
+        e isa Base.IOError || rethrow() # `path` cannot be determined to be a file
+    end && return false
+    # ...and except if there's already a " at the cursor.
+    return lastindex(str) <= pos || str[nextind(str, pos)] != '"'
+end
+
+
 function bslash_completions(string::String, pos::Int)
     slashpos = something(findprev(isequal('\\'), string, pos), 0)
     if (something(findprev(in(bslash_separators), string, pos), 0) < slashpos &&
@@ -747,13 +773,8 @@ function completions(string::String, pos::Int, context_module::Module=Main)
 
         paths, r, success = complete_path(replace(string[r], r"\\ " => " "), pos)
 
-        if inc_tag === :string &&
-           length(paths) == 1 &&  # Only close if there's a single choice,
-           !isdir(expanduser(replace(string[startpos:prevind(string, first(r))] * paths[1].path,
-                                     r"\\ " => " "))) &&  # except if it's a directory
-           (lastindex(string) <= pos ||
-            string[nextind(string,pos)] != '"')  # or there's already a " at the cursor.
-            paths[1] = PathCompletion(paths[1].path * "\"")
+        if inc_tag === :string && close_path_completion(string, startpos, r, paths, pos)
+            paths[1] = PathCompletion((paths[1]::PathCompletion).path * "\"")
         end
 
         #Latex symbols can be completed for strings

stdlib/REPL/test/replcompletions.jl

@@ -31,6 +31,25 @@ let ex = quote
         macro foobar()
             :()
         end
+        macro barfoo(ex)
+            ex
+        end
+        macro error_expanding()
+            error("cannot expand @error_expanding")
+            :()
+        end
+        macro error_lowering_conditional(a)
+            if isa(a, Number)
+                return a
+            end
+            throw(AssertionError("Not a Number"))
+            :()
+        end
+        macro error_throwing()
+            return quote
+                error("@error_throwing throws an error")
+            end
+        end
 
         primitive type NonStruct 8 end
         Base.propertynames(::NonStruct) = (:a, :b, :c)
@@ -813,6 +832,45 @@ let s, c, r
 end
 end
 
+#test that it does not crash on files for which `stat` errors
+let current_dir, forbidden
+    # Issue #36855
+    if !Sys.iswindows() || Sys.windows_version() >= Sys.WINDOWS_VISTA_VER
+        mktempdir() do path
+            selfsymlink = joinpath(path, "selfsymlink")
+            symlink(selfsymlink, selfsymlink)
+            @test try
+                stat(selfsymlink) # should crash with a IOError
+                false
+            catch e
+                e isa Base.IOError && occursin("ELOOP", e.msg)
+            end
+            c, r = test_complete("\"$(joinpath(path, "selfsym"))")
+            @test c == ["selfsymlink"]
+        end
+    end
+
+    # Issue #32797
+    forbidden = Sys.iswindows() ? "C:\\S" : "/root/x"
+    test_complete(forbidden); @test true # simply check that it did not crash
+
+     # Issue #19310
+    if Sys.iswindows()
+        current_dir = pwd()
+        cd("C:")
+        test_complete("C"); @test true
+        test_complete("C:"); @test true
+        test_complete("C:\\"); @test true
+        if isdir("D:")
+            cd("D:")
+            test_complete("C"); @test true
+            test_complete("C:"); @test true
+            test_complete("C:\\"); @test true
+        end
+        cd(current_dir)
+    end
+end
+
 #test that it can auto complete with spaces in file/path
 mktempdir() do path
     space_folder = randstring() * " α"
@@ -1161,6 +1219,26 @@ let
     (test_complete("@Main.noexist."); @test true)
 end
 
+let # Check that completion does not crash on (possibly invalid) macro calls
+    (test_complete("@show."); @test true)
+    (test_complete("@macroexpand."); @test true)
+    (test_complete("@.."); @test true)
+    (test_complete("CompletionFoo.@foobar."); @test true)
+    (test_complete("CompletionFoo.@foobar()."); @test true)
+    (test_complete("CompletionFoo.@foobar(4)."); @test true)
+    (test_complete("CompletionFoo.@barfoo."); @test true)
+    (test_complete("CompletionFoo.@barfoo()."); @test true)
+    (test_complete("CompletionFoo.@barfoo(6)."); @test true)
+    (test_complete("CompletionFoo.@error_expanding."); @test true)
+    (test_complete("CompletionFoo.@error_expanding()."); @test true)
+    (test_complete("CompletionFoo.@error_lowering_conditional."); @test true)
+    (test_complete("CompletionFoo.@error_lowering_conditional()."); @test true)
+    (test_complete("CompletionFoo.@error_lowering_conditional(3)."); @test true)
+    (test_complete("CompletionFoo.@error_lowering_conditional('a')."); @test true)
+    (test_complete("CompletionFoo.@error_throwing."); @test true)
+    (test_complete("CompletionFoo.@error_throwing()."); @test true)
+end
+
 @testset "https://github.com/JuliaLang/julia/issues/40247" begin
     # getfield type completion can work for complicated expression