vlib.os: fix join-path

Closes #20231

vlib/os/os.v

@@ -570,54 +570,49 @@ pub fn is_file(path string) bool {
 // them with a platform-specific path_separator. Empty elements are ignored.
 @[manualfree]
 pub fn join_path(base string, dirs ...string) string {
- // TODO: fix freeing of `dirs` when the passed arguments are variadic,
- // but do not free the arr, when `os.join_path(base, ...arr)` is called.
- mut sb := strings.new_builder(base.len + dirs.len * 50)
+ mut sb := strings.new_builder(256)
  defer {
  unsafe { sb.free() }
  }
- sbase := base.trim_right('\\/')
- defer {
- unsafe { sbase.free() }
+ mut i := 0
+ if base != '' {
+ sb.write_string(base)
+ } else {
+ for i < dirs.len {
+ d := dirs[i]
+ if d != '' {
+ sb.write_string(d)
+ break
+ }
+ i++
+ }
  }
- sb.write_string(sbase)
- for d in dirs {
+ for i < dirs.len {
+  d := dirs[i]
  if d != '' {
  sb.write_string(path_separator)
  sb.write_string(d)
  }
+ i++
  }
- mut res := sb.str()
- if sbase == '' {
- res = res.trim_left(path_separator)
- }
- if res.contains('/./') {
- // Fix `join_path("/foo/bar", "./file.txt")` => `/foo/bar/./file.txt`
- res = res.replace('/./', '/')
- }
+ res := sb.str()
  return res
 }
 
 // join_path_single appends the `elem` after `base`, separated with a
 // platform-specific path_separator. Empty elements are ignored.
-@[manualfree]
 pub fn join_path_single(base string, elem string) string {
  // TODO: deprecate this and make it `return os.join_path(base, elem)`,
  // when freeing variadic args vs ...arr is solved in the compiler
- mut sb := strings.new_builder(base.len + elem.len + 1)
- defer {
- unsafe { sb.free() }
- }
- sbase := base.trim_right('\\/')
- defer {
- unsafe { sbase.free() }
- }
- if base != '' {
- sb.write_string(sbase)
- sb.write_string(path_separator)
+ if base != '' && elem != '' {
+ return '${base}${path_separator}${elem}'
+ } else if base != '' {
+ return base
+ } else if elem != '' {
+ return elem
+ } else {
+ return ''
  }
- sb.write_string(elem)
- return sb.str()
 }
 
 // walk_ext returns a recursive list of all files in `path` ending with `ext`.

vlib/os/os_test.c.v

@@ -621,9 +621,10 @@ fn test_join() {
  assert os.join_path('v', '', 'dir') == 'v\\dir'
  } $else {
  assert os.join_path('v', 'vlib', 'os') == 'v/vlib/os'
- assert os.join_path('/foo/bar', './file.txt') == '/foo/bar/file.txt'
+ assert os.join_path('/foo/bar', './file.txt') == '/foo/bar/./file.txt'
  assert os.join_path('', 'f1', 'f2') == 'f1/f2'
  assert os.join_path('v', '', 'dir') == 'v/dir'
+ assert os.join_path('/', 'test') == '/test'
  }
 }