Add: support filtering content entries for patchpacks

This changes nothing for us, but allows patchpacks to add the
right pieces of code to start filtering content entries on patchpack
only entries.

(cherry picked from commit 77860bb61e61307e4d9cf869ba62be8ca4d9d9b3)

src/network/core/tcp_content.h

@@ -28,7 +28,11 @@ protected:
 	/**
 	 * Client requesting a list of content info:
 	 *  byte    type
-	 *  uint32  openttd version
+	 *  uint32  openttd version (or 0xFFFFFFFF if using a list)
+	 * Only if the above value is 0xFFFFFFFF:
+	 *  uint8   count
+	 *  string  branch-name ("vanilla" for upstream OpenTTD)
+	 *  string  release version (like "12.0")
 	 * @param p The packet that was just received.
 	 * @return True upon success, otherwise false.
 	 */

src/network/network_content.cpp

@@ -207,7 +207,20 @@ void ClientNetworkContentSocketHandler::RequestContentList(ContentType type)
 
 	Packet *p = new Packet(PACKET_CONTENT_CLIENT_INFO_LIST);
 	p->Send_uint8 ((byte)type);
-	p->Send_uint32(_openttd_newgrf_version);
+	p->Send_uint32(0xffffffff);
+	p->Send_uint8 (1);
+	p->Send_string("vanilla");
+	p->Send_string(_openttd_content_version);
+
+	/* Patchpacks can extend the list with one. In BaNaNaS metadata you can
+	 * add a branch in the 'compatibility' list, to filter on this. If you want
+	 * your patchpack to be mentioned in the BaNaNaS web-interface, create an
+	 * issue on https://github.com/OpenTTD/bananas-api asking for this.
+
+	p->Send_string("patchpack"); // Or what-ever the name of your patchpack is.
+	p->Send_string(_openttd_content_version_patchpack);
+
+	*/
 
 	this->SendPacket(p);
 }

src/rev.cpp.in

@@ -79,6 +79,13 @@ const byte _openttd_revision_modified = ${REV_MODIFIED};
  */
 const byte _openttd_revision_tagged = ${REV_ISTAG};
 
+/**
+ * To check compatibility of BaNaNaS content, this version string is used.
+ * It should never contain things like "beta", but only the release version
+ * we are compatible with.
+ */
+const char _openttd_content_version[] = "12.0";
+
 /**
  * The NewGRF revision of OTTD:
  * bits  meaning.

src/rev.h

@@ -18,6 +18,7 @@ extern const char _openttd_revision_year[];
 extern const char _openttd_build_configure_defines[];
 extern const byte _openttd_revision_modified;
 extern const byte _openttd_revision_tagged;
+extern const char _openttd_content_version[];
 extern const uint32 _openttd_newgrf_version;
 
 bool IsReleasedVersion();