AK: Make FileSystemPath better at handling relative paths

Relative paths now canonicalize into a string starting with "./"
Previously, "foo" would be canonicalized as "/foo" which was clearly
not right.

AK/FileSystemPath.cpp

@@ -14,13 +14,26 @@ FileSystemPath::FileSystemPath(const StringView& s)
 
 void FileSystemPath::canonicalize()
 {
+ if (m_string.is_empty()) {
+ m_parts.clear();
+ return;
+ }
+
+ bool is_absolute_path = m_string[0] == '/';
  auto parts = m_string.split_view('/');
+
+ if (!is_absolute_path)
+ parts.prepend(".");
+
  int approximate_canonical_length = 0;
  Vector<String> canonical_parts;
 
- for (auto& part : parts) {
- if (part == ".")
- continue;
+ for (int i = 0; i < parts.size(); ++i) {
+ auto& part = parts[i];
+ if (is_absolute_path || i != 0) {
+ if (part == ".")
+ continue;
+ }
  if (part == "..") {
  if (!canonical_parts.is_empty())
  canonical_parts.take_last();
@@ -43,9 +56,11 @@ void FileSystemPath::canonicalize()
  m_extension = name_parts[1];
 
  StringBuilder builder(approximate_canonical_length);
- for (auto& cpart : canonical_parts) {
- builder.append('/');
- builder.append(cpart);
+ for (int i = 0; i < canonical_parts.size(); ++i) {
+ auto& canonical_part = canonical_parts[i];
+ if (is_absolute_path || i != 0)
+ builder.append('/');
+ builder.append(canonical_part);
  }
  m_parts = move(canonical_parts);
  m_string = builder.to_string();

AK/Tests/TestFileSystemPath.cpp

@@ -26,4 +26,37 @@ TEST_CASE(dotdot_coalescing)
  EXPECT_EQ(FileSystemPath("/../../../../").string(), "/");
 }
 
+TEST_CASE(relative_paths)
+{
+ {
+ FileSystemPath path("simple");
+ EXPECT_EQ(path.is_valid(), true);
+ EXPECT_EQ(path.string(), "./simple");
+ EXPECT_EQ(path.parts().size(), 2);
+ EXPECT_EQ(path.basename(), "simple");
+ }
+ {
+ FileSystemPath path("a/relative/path");
+ EXPECT_EQ(path.is_valid(), true);
+ EXPECT_EQ(path.string(), "./a/relative/path");
+ EXPECT_EQ(path.parts().size(), 4);
+ EXPECT_EQ(path.basename(), "path");
+ }
+ {
+ FileSystemPath path("./././foo");
+ EXPECT_EQ(path.is_valid(), true);
+ EXPECT_EQ(path.string(), "./foo");
+ EXPECT_EQ(path.parts().size(), 2);
+ EXPECT_EQ(path.basename(), "foo");
+ }
+
+ {
+ FileSystemPath path(".");
+ EXPECT_EQ(path.is_valid(), true);
+ EXPECT_EQ(path.string(), ".");
+ EXPECT_EQ(path.parts().size(), 1);
+ EXPECT_EQ(path.basename(), ".");
+ }
+}
+
 TEST_MAIN(FileSystemPath)