Commit 035c1b65229083e01bc5ec69f2ad529ba0c56062 | zig

author	Igor Anić <igor.anic@gmail.com> 2024-04-11 16:32:07+02:00
committer	Andrew Kelley <andrew@ziglang.org> 2024-07-03 12:12:50-07:00
log	035c1b65229083e01bc5ec69f2ad529ba0c56062
tree	b7e5ed6d5e6d2da7a8f19d68191ad748ff1bc83a
parent	fe66a12a23eda90b89b06dc28957f3baac01ee89

std.tar: add strip components error to diagnostics

This was the only kind of error which was raised in pipeToFileSystem and
not added to Diagnostics.
Shell tar silently ignores paths which are stripped out when used with
`--strip-components` switch. This enables that same behavior, errors
will be collected in diagnostics but caller is free to ignore that type
of diagnostics errors.
Enables use case where caller knows structure of the tar file and want
to extract only some deeply nested folders ignoring upper files/folders.

Fixes: #17620 by giving caller options:
- not provide diagnostic and get errors
- provide diagnostics and analyze errors
- provide diagnostics and ignore errors

2 files changed, 39 insertions(+), 3 deletions(-)

lib
- std
  - tar.zig
src
- Package
  - Fetch.zig

lib/std/tar.zig+38-3

 @@ -46,6 +46,9 @@ pub const Diagnostics = struct {
             file_name: []const u8,
             file_type: Header.Kind,
         },
+        components_outside_stripped_prefix: struct {
+            file_name: []const u8,
+        },
     };
     fn findRoot(d: *Diagnostics, path: []const u8) !void {
 @@ -97,6 +100,9 @@ pub const Diagnostics = struct {
                 .unsupported_file_type => |info| {
                     d.allocator.free(info.file_name);
                 },
+                .components_outside_stripped_prefix => |info| {
+                    d.allocator.free(info.file_name);
+                },
             }
         }
         d.errors.deinit(d.allocator);
 @@ -623,18 +629,24 @@ pub fn pipeToFileSystem(dir: std.fs.Dir, reader: anytype, options: PipeOptions)
     while (try iter.next()) |file| {
         const file_name = stripComponents(file.name, options.strip_components);
+        if (file_name.len == 0 and file.kind != .directory) {
+            const d = options.diagnostics orelse return error.TarComponentsOutsideStrippedPrefix;
+            try d.errors.append(d.allocator, .{ .components_outside_stripped_prefix = .{
+                .file_name = try d.allocator.dupe(u8, file.name),
+            } });
+            continue;
+        }
         if (options.diagnostics) |d| {
             try d.findRoot(file_name);
         }
         switch (file.kind) {
             .directory => {
-                if (file_name.len != 0 and !options.exclude_empty_directories) {
+                if (file_name.len > 0 and !options.exclude_empty_directories) {
                     try dir.makePath(file_name);
                 }
             },
             .file => {
-                if (file_name.len == 0) return error.BadFileName;
                 if (createDirAndFile(dir, file_name, fileMode(file.mode, options))) |fs_file| {
                     defer fs_file.close();
                     try file.writeAll(fs_file);
 @@ -647,7 +659,6 @@ pub fn pipeToFileSystem(dir: std.fs.Dir, reader: anytype, options: PipeOptions)
                 }
             },
             .sym_link => {
-                if (file_name.len == 0) return error.BadFileName;
                 const link_name = file.link_name;
                 createDirAndSymlink(dir, link_name, file_name) catch |err| {
                     const d = options.diagnostics orelse return error.UnableToCreateSymLink;
 @@ -1096,6 +1107,30 @@ test "findRoot without explicit root dir" {
     try testing.expectEqualStrings("root", diagnostics.root_dir);
 }
+test "pipeToFileSystem strip_components" {
+    const data = @embedFile("tar/testdata/example.tar");
+    var fbs = std.io.fixedBufferStream(data);
+    const reader = fbs.reader();
+    var tmp = testing.tmpDir(.{ .no_follow = true });
+    defer tmp.cleanup();
+    var diagnostics: Diagnostics = .{ .allocator = testing.allocator };
+    defer diagnostics.deinit();
+    pipeToFileSystem(tmp.dir, reader, .{
+        .strip_components = 3,
+        .diagnostics = &diagnostics,
+    }) catch |err| {
+        // Skip on platform which don't support symlinks
+        if (err == error.UnableToCreateSymLink) return error.SkipZigTest;
+        return err;
+    };
+    try testing.expectEqual(2, diagnostics.errors.items.len);
+    try testing.expectEqualStrings("example/b/symlink", diagnostics.errors.items[0].components_outside_stripped_prefix.file_name);
+    try testing.expectEqualStrings("example/a/file", diagnostics.errors.items[1].components_outside_stripped_prefix.file_name);
+}
 fn normalizePath(bytes: []u8) []u8 {
     const canonical_sep = std.fs.path.sep_posix;
     if (std.fs.path.sep == canonical_sep) return bytes;

src/Package/Fetch.zig+1

...	@@ -1189,6 +1189,7 @@ fn unpackTarball(f: *Fetch, out_dir: fs.Dir, reader: anytype) RunError!UnpackRes	...	@@ -1189,6 +1189,7 @@ fn unpackTarball(f: *Fetch, out_dir: fs.Dir, reader: anytype) RunError!UnpackRes
1189	.unable_to_create_file => \|i\| res.unableToCreateFile(stripRoot(i.file_name, res.root_dir), i.code),	1189	.unable_to_create_file => \|i\| res.unableToCreateFile(stripRoot(i.file_name, res.root_dir), i.code),
1190	.unable_to_create_sym_link => \|i\| res.unableToCreateSymLink(stripRoot(i.file_name, res.root_dir), i.link_name, i.code),	1190	.unable_to_create_sym_link => \|i\| res.unableToCreateSymLink(stripRoot(i.file_name, res.root_dir), i.link_name, i.code),
1191	.unsupported_file_type => \|i\| res.unsupportedFileType(stripRoot(i.file_name, res.root_dir), @intFromEnum(i.file_type)),	1191	.unsupported_file_type => \|i\| res.unsupportedFileType(stripRoot(i.file_name, res.root_dir), @intFromEnum(i.file_type)),
		1192	.components_outside_stripped_prefix => {}, // impossible with strip_components = 0
1192	}	1193	}
1193	}	1194	}
1194	}	1195	}