Fix crystal overrides (#2295)

* Move Crystal stdlib classes overrides to a separate file
* Document known crystal overrides
* Update crystal overrides for HTTP::Client socket
* Update shard.yml to restrict crystal versions
* Fix compilation error in Crystal 1.1.x (See
   https://github.com/crystal-lang/crystal/issues/10965
   for more details about this issue).

shard.yml

@@ -26,6 +26,6 @@ dependencies:
     github: iv-org/lsquic.cr
     version: ~> 2.18.1-2
 
-crystal: 1.0.0
+crystal: ">= 1.0.0, < 2.0.0"
 
 license: AGPLv3

src/invidious/helpers/crystal_class_overrides.cr

@@ -0,0 +1,70 @@
+# Override of the TCPSocket and HTTP::Client classes in oder to allow an
+# IP family to be selected for domains that resolve to both IPv4 and
+# IPv6 addresses.
+#
+class TCPSocket
+  def initialize(host : String, port, dns_timeout = nil, connect_timeout = nil, family = Socket::Family::UNSPEC)
+    Addrinfo.tcp(host, port, timeout: dns_timeout, family: family) do |addrinfo|
+      super(addrinfo.family, addrinfo.type, addrinfo.protocol)
+      connect(addrinfo, timeout: connect_timeout) do |error|
+        close
+        error
+      end
+    end
+  end
+end
+
+# :ditto:
+class HTTP::Client
+  property family : Socket::Family = Socket::Family::UNSPEC
+
+  private def io
+    io = @io
+    return io if io
+    unless @reconnect
+      raise "This HTTP::Client cannot be reconnected"
+    end
+
+    hostname = @host.starts_with?('[') && @host.ends_with?(']') ? @host[1..-2] : @host
+    io = TCPSocket.new hostname, @port, @dns_timeout, @connect_timeout, @family
+    io.read_timeout = @read_timeout if @read_timeout
+    io.write_timeout = @write_timeout if @write_timeout
+    io.sync = false
+
+    {% if !flag?(:without_openssl) %}
+      if tls = @tls
+        tcp_socket = io
+        begin
+          io = OpenSSL::SSL::Socket::Client.new(tcp_socket, context: tls, sync_close: true, hostname: @host)
+        rescue exc
+          # don't leak the TCP socket when the SSL connection failed
+          tcp_socket.close
+          raise exc
+        end
+      end
+    {% end %}
+
+    @io = io
+  end
+end
+
+# Mute the ClientError exception raised when a connection is flushed.
+# This happends when the connection is unexpectedly closed by the client.
+#
+class HTTP::Server::Response
+  class Output
+    private def unbuffered_flush
+      @io.flush
+    rescue ex : IO::Error
+      unbuffered_close
+    end
+  end
+end
+
+# TODO: Document this override
+#
+class PG::ResultSet
+  def field(index = @column_index)
+    @fields.not_nil![index]
+  end
+end

src/invidious/helpers/helpers.cr

@@ -509,12 +509,6 @@ def check_table(db, table_name, struct_type = nil)
   end
 end
 
-class PG::ResultSet
-  def field(index = @column_index)
-    @fields.not_nil![index]
-  end
-end
-
 def get_column_array(db, table_name)
   column_array = [] of String
   db.query("SELECT * FROM #{table_name} LIMIT 0") do |rs|
@@ -699,47 +693,3 @@ def proxy_file(response, env)
     IO.copy response.body_io, env.response
   end
 end
-
-class HTTP::Server::Response
-  class Output
-    private def unbuffered_flush
-      @io.flush
-    rescue ex : IO::Error
-      unbuffered_close
-    end
-  end
-end
-
-class HTTP::Client
-  property family : Socket::Family = Socket::Family::UNSPEC
-
-  private def socket
-    socket = @socket
-    return socket if socket
-
-    hostname = @host.starts_with?('[') && @host.ends_with?(']') ? @host[1..-2] : @host
-    socket = TCPSocket.new hostname, @port, @dns_timeout, @connect_timeout, @family
-    socket.read_timeout = @read_timeout if @read_timeout
-    socket.sync = false
-
-    {% if !flag?(:without_openssl) %}
-      if tls = @tls
-        socket = OpenSSL::SSL::Socket::Client.new(socket, context: tls, sync_close: true, hostname: @host)
-      end
-    {% end %}
-
-    @socket = socket
-  end
-end
-
-class TCPSocket
-  def initialize(host, port, dns_timeout = nil, connect_timeout = nil, family = Socket::Family::UNSPEC)
-    Addrinfo.tcp(host, port, timeout: dns_timeout, family: family) do |addrinfo|
-      super(addrinfo.family, addrinfo.type, addrinfo.protocol)
-      connect(addrinfo, timeout: connect_timeout) do |error|
-        close
-        error
-      end
-    end
-  end
-end