Fix UPNP on windows after #30205.

The problem could be related to different byte ordering when copying
the interface address over the binding address.

thirdparty/README.md

@@ -281,6 +281,7 @@ Files extracted from upstream source:
 - All `*.c` and `*.h` files from `miniupnpc` to `thirdparty/miniupnpc/miniupnpc`
 - Remove `test*`, `minihttptestserver.c` and `wingenminiupnpcstrings.c`
 
+The patch `windows_fix.diff` is applied to `minissdpc.c` to fix an upstream issue.
 The only modified file is miniupnpcstrings.h, which was created for Godot
 (it is usually autogenerated by cmake).
 

thirdparty/miniupnpc/miniupnpc/minissdpc.c

@@ -683,11 +683,7 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
 #endif
 		} else {
 			struct in_addr mc_if;
-#if defined(_WIN32) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
-			InetPtonA(AF_INET, multicastif, &mc_if);
-#else
 			mc_if.s_addr = inet_addr(multicastif); /* ex: 192.168.x.x */
-#endif
 			if(mc_if.s_addr != INADDR_NONE)
 			{
 				((struct sockaddr_in *)&sockudp_r)->sin_addr.s_addr = mc_if.s_addr;

thirdparty/miniupnpc/windows_fix.diff

@@ -0,0 +1,16 @@
+diff --git a/thirdparty/miniupnpc/miniupnpc/minissdpc.c b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
+index 29f8110155..ea9af02e1f 100644
+--- a/thirdparty/miniupnpc/miniupnpc/minissdpc.c
++++ b/thirdparty/miniupnpc/miniupnpc/minissdpc.c
+@@ -683,11 +683,7 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
+ #endif
+ 		} else {
+ 			struct in_addr mc_if;
+-#if defined(_WIN32) && (_WIN32_WINNT >= _WIN32_WINNT_VISTA)
+-			InetPtonA(AF_INET, multicastif, &mc_if);
+-#else
+ 			mc_if.s_addr = inet_addr(multicastif); /* ex: 192.168.x.x */
+-#endif
+ 			if(mc_if.s_addr != INADDR_NONE)
+ 			{
+ 				((struct sockaddr_in *)&sockudp_r)->sin_addr.s_addr = mc_if.s_addr;