DumpDir reads back absolute and without a trailing slash

A relative DumpDir read back as written, relative, and a trailing / stayed. It now resolves against the directory pardes started in, as a Dump already did, and is shown cleaned.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 22 insertions, 3 deletions

diff --git a/src/dump.zig b/src/dump.zig
index 0e911ec1..45a5e0eb 100644
--- a/src/dump.zig
+++ b/src/dump.zig
@@ -64,9 +64,28 @@ fn hostEnv(name: [*:0]const u8) ?[*:0]u8 {
 /// setting when set (a leading `~/` is the home directory), else the default.
 pub fn directory(buf: []u8, dir_setting: []const u8) ?[]const u8 {
     if (dir_setting.len == 0) return defaultDirectory(buf);
-    if (std.mem.startsWith(u8, dir_setting, "~/")) if (hostEnv("HOME")) |h|
-        return std.fmt.bufPrint(buf, "{s}/{s}", .{ std.mem.span(h), dir_setting[2..] }) catch null;
-    return std.fmt.bufPrint(buf, "{s}", .{dir_setting}) catch null;
+    var joined: [2048]u8 = undefined;
+    // `~/x`, else a relative one from the directory pardes started in: the
+    // same place however it was written, and shown so.
+    const raw = if (std.mem.startsWith(u8, dir_setting, "~/")) (if (hostEnv("HOME")) |h|
+        std.fmt.bufPrint(&joined, "{s}/{s}", .{ std.mem.span(h), dir_setting[2..] }) catch return null
+    else
+        dir_setting) else dir_setting;
+    var fba_buf: [4096]u8 = undefined;
+    var fba = std.heap.FixedBufferAllocator.init(&fba_buf);
+    var cwd_buf: [1024]u8 = undefined;
+    // No libc on the web or the board: there a relative one is from `/`.
+    const cwd: []const u8 = if (comptime !pardes.hosted) "/" else if (std.fs.path.isAbsolute(raw)) "/" else if (std.c.getcwd(&cwd_buf, cwd_buf.len)) |c| std.mem.span(@as([*:0]const u8, @ptrCast(c))) else "/";
+    const resolved = std.fs.path.resolvePosix(fba.allocator(), &.{ cwd, raw }) catch return null;
+    return std.fmt.bufPrint(buf, "{s}", .{resolved}) catch null;
+}
+
+test "a DumpDir reads back absolute, however it was written" {
+    var buf: [4096]u8 = undefined;
+    try std.testing.expectEqualStrings("/tmp/dumps", directory(&buf, "/tmp/dumps/").?);
+    try std.testing.expectEqualStrings("/tmp/dumps", directory(&buf, "/tmp//x/../dumps").?);
+    const rel = directory(&buf, "rel/");
+    try std.testing.expect(std.fs.path.isAbsolute(rel.?) and std.mem.endsWith(u8, rel.?, "/rel"));
 }
 
 /// The standard dump directory, without creating it or generating a filename.