handle relative paths with too many ".."

Author: marler8997

lib/std/os/windows.zig

@@ -1825,12 +1825,35 @@ pub fn sliceToPrefixedFileW(s: []const u8) !PathSpace {
     path_space.len = start_index + try std.unicode.utf8ToUtf16Le(path_space.data[start_index..], s);
     if (path_space.len > path_space.data.len) return error.NameTooLong;
     path_space.len = start_index + (normalizePath(u16, path_space.data[start_index..path_space.len]) catch |err| switch (err) {
-        error.TooManyParentDirs => return error.BadPathName,
+        error.TooManyParentDirs => {
+            if (!std.fs.path.isAbsolute(s)) {
+                var temp_path: PathSpace = undefined;
+                temp_path.len = try std.unicode.utf8ToUtf16Le(&temp_path.data, s);
+                std.debug.assert(temp_path.len == path_space.len);
+                temp_path.data[path_space.len] = 0;
+                path_space = try getFullPathNameW(&temp_path.data);
+                std.debug.assert(path_space.data[path_space.len] == 0);
+                return path_space;
+            }
+            return error.BadPathName;
+        },
     });
     path_space.data[path_space.len] = 0;
     return path_space;
 }
 
+fn getFullPathNameW(path: [*:0]const u16) !PathSpace {
+    // TODO https://github.com/ziglang/zig/issues/2765
+    var path_space: PathSpace = undefined;
+    path_space.len = kernel32.GetFullPathNameW(path, path_space.data.len, &path_space.data, null);
+    if (path_space.len == 0) {
+        switch (kernel32.GetLastError()) {
+            else => |err| return unexpectedError(err),
+        }
+    }
+    return path_space;
+}
+
 /// Assumes an absolute path.
 pub fn wToPrefixedFileW(s: []const u16) !PathSpace {
     // TODO https://github.com/ziglang/zig/issues/2765

lib/std/os/windows/kernel32.zig

@@ -136,6 +136,13 @@ pub extern "kernel32" fn GetFinalPathNameByHandleW(
     dwFlags: DWORD,
 ) callconv(WINAPI) DWORD;
 
+pub extern "kernel32" fn GetFullPathNameW(
+    lpFileName: [*:0]const u16,
+    nBufferLength: u32,
+    lpBuffer: ?[*:0]u16,
+    lpFilePart: ?*?[*:0]u16,
+) callconv(@import("std").os.windows.WINAPI) u32;
+
 pub extern "kernel32" fn GetOverlappedResult(hFile: HANDLE, lpOverlapped: *OVERLAPPED, lpNumberOfBytesTransferred: *DWORD, bWait: BOOL) callconv(WINAPI) BOOL;
 
 pub extern "kernel32" fn GetProcessHeap() callconv(WINAPI) ?HANDLE;