From 10002ccce90ea914de7fbf90d876f3f987d7b527 Mon Sep 17 00:00:00 2001
From: Henrik Holst <6200749+hholst80@users.noreply.github.com>
Date: Sun, 5 May 2024 00:45:55 +0200
Subject: [PATCH] vlib.os: fix join-path

Closes #20231
---
 vlib/os/os.v        | 55 +++++++++++++++++++++------------------------
 vlib/os/os_test.c.v |  3 ++-
 2 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/vlib/os/os.v b/vlib/os/os.v
index 25e6044d618dae..327a97b81b62f7 100644
--- a/vlib/os/os.v
+++ b/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`.
diff --git a/vlib/os/os_test.c.v b/vlib/os/os_test.c.v
index 135f1bc733c819..8852501334b448 100644
--- a/vlib/os/os_test.c.v
+++ b/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'
 	}
 }