setup: Show error when server address not entered.

Don't launch the game if a server address has not been entered; show a
message to the user instead. This fixes #121.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/setup/multiplayer.c b/src/setup/multiplayer.c
index b151a10d..35552349 100644
--- a/src/setup/multiplayer.c
+++ b/src/setup/multiplayer.c
@@ -795,6 +795,13 @@ static void DoJoinGame(void *unused1, void *unused2)
 {
     execute_context_t *exec;
 
+    if (connect_address == NULL || strlen(connect_address) <= 0)
+    {
+        TXT_MessageBox(NULL, "Please enter a server address\n"
+                             "to connect to.");
+        return;
+    }
+
     exec = NewExecuteContext();
 
     AddCmdLineParameter(exec, "-connect %s", connect_address);