LaunchServer: Resolve symlinks when querying for handler application

This lets us launch proper handler application for symlinks :^)

Userland/Services/LaunchServer/Launcher.cpp

@@ -12,6 +12,7 @@
 #include <AK/LexicalPath.h>
 #include <AK/StringBuilder.h>
 #include <LibCore/ConfigFile.h>
+#include <LibCore/File.h>
 #include <LibDesktop/AppFile.h>
 #include <errno.h>
 #include <serenity.h>
@@ -252,8 +253,8 @@ void Launcher::for_each_handler(const String& key, HashMap<String, String>& user
 void Launcher::for_each_handler_for_path(const String& path, Function<bool(const Handler&)> f)
 {
  struct stat st;
- if (stat(path.characters(), &st) < 0) {
- perror("stat");
+ if (lstat(path.characters(), &st) < 0) {
+ perror("lstat");
  return;
  }
 
@@ -269,6 +270,13 @@ void Launcher::for_each_handler_for_path(const String& path, Function<bool(const
  if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode))
  return;
 
+ if (S_ISLNK(st.st_mode)) {
+ auto real_path = Core::File::real_path_for(String::formatted("{}/{}", LexicalPath::dirname(path), Core::File::read_link(path)));
+ return for_each_handler_for_path(real_path, [&](const auto& handler) -> bool {
+ return f(handler);
+ });
+ }
+
  if ((st.st_mode & S_IFMT) == S_IFREG && (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
  f(get_handler_for_executable(Handler::Type::Application, path));