Added function normalize_path to convert filenames to an absolute path.

src/filesystem.cpp

@@ -1103,6 +1103,83 @@ std::string get_wml_location(const std::string &filename, const std::string &cur
 	return result;
 }
 
+static bool is_path_sep(char c)
+{
+#ifdef _WIN32
+	if (c == '/' || c == '\\') return true;
+#else
+	if (c == '/') return true;
+#endif
+	return false;
+}
+
+std::string normalize_path(const std::string &p1)
+{
+	if (p1.empty()) return p1;
+
+	std::string p2;
+#ifdef _WIN32
+	if (p1.size() >= 2 && p1[1] == ':')
+		// Windows relative paths with explicit drive name are not handled.
+		p2 = p1;
+	else
+#endif
+	if (!is_path_sep(p1[0]))
+		p2 = std::string(get_cwd()) + "/" + p1;
+	else
+		p2 = p1;
+
+#ifdef _WIN32
+	std::string drive;
+	if (p2.size() >= 2 && p2[1] == ':') {
+		drive = p2.substr(0, 2);
+		p2.erase(0, 2);
+	}
+#endif
+
+	const char *p3 = p2.c_str();
+
+	std::vector<std::string> components(1);
+	for (int i = 0, i_end = p2.size(); i <= i_end; ++i)
+	{
+		std::string &last = components[components.size() - 1];
+		char c = p2[i];
+		if (is_path_sep(c) || c == 0)
+		{
+			if (last == ".")
+				last.clear();
+			else if (last == "..")
+			{
+				if (components.size() >= 2) {
+					components.pop_back();
+					components[components.size() - 1].clear();
+				} else
+					last.clear();
+			}
+			else if (!last.empty())
+				components.push_back(std::string());
+		}
+		else
+			last += c;
+	}
+
+	std::ostringstream p4;
+	components.pop_back();
+
+#ifdef _WIN32
+	p4 << drive;
+#endif
+
+	foreach (const std::string &s, components)
+	{
+		p4 << '/' << s;
+	}
+
+	DBG_FS << "Normalizing '" << p2 << "' to '" << p4.str() << "'\n";
+
+	return p4.str();
+}
+
 scoped_istream& scoped_istream::operator=(std::istream *s)
 {
 	delete stream;

src/filesystem.hpp

@@ -165,6 +165,11 @@ std::string file_name(const std::string& file);
  */
 std::string directory_name(const std::string& file);
 
+/**
+ * Returns the absolute path of a file.
+ */
+std::string normalize_path(const std::string &path);
+
 /**
  *  The paths manager is responsible for recording the various paths
  *  that binary files may be located at.