cmd/tests: Test paths that exceed MAX_PATH.

programs/cmd/tests/test_builtins.cmd

@@ -3333,6 +3333,25 @@ if errorlevel 1 echo Normal+tab+garbage drive change failed
 
 popd
 
+echo ------------ Testing length wrt. MAX_PATH ------------
+rem native cmd limits all path lengths to MAX_PATH=260
+pushd c:\
+set depth=25
+for /L %%d in (0,1,25) do (
+  mkdir abcdefghij > NUL 2>&1
+  if exist abcdefghij (
+     cd abcdefghij
+     set depth=%%d
+  )
+)
+echo %depth%
+rem even relative paths are transformed to absolute, and tested against MAX_PATH
+echo abc > 01234567890123
+if exist 01234567890123 (echo Success) else echo Failure
+echo abc > 012345678901234
+if exist 012345678901234 (echo Failure) else echo Success
+popd
+rmdir /s /q c:\abcdefghij
 echo ------------ Testing combined CALLs/GOTOs ------------
 echo @echo off>foo.cmd
 echo goto :eof>>foot.cmd

programs/cmd/tests/test_builtins.cmd.exp

@@ -1687,6 +1687,10 @@ Normal+space+garbage
 Quoted should fail
 Normal+tab
 Normal+tab+garbage
+------------ Testing length wrt. MAX_PATH ------------
+@todo_wine@21
+Success
+@todo_wine@Success
 ------------ Testing combined CALLs/GOTOs ------------
 world
 cheball