Argh. With DEBUG and MALLOC_LOG enabled, I found output intended for the

console was ending up in one or other of debug.log or putty_mem.log. I
don't really understand why, but I've put some extra paranoia and caching
in debug(()) and that seems to have fixed it (tm). Perhaps I can get back
to debugging...

[originally from svn r2291]

misc.c

@@ -592,6 +592,7 @@ void safefree(void *ptr)
 
 #ifdef DEBUG
 static FILE *debug_fp = NULL;
+static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
 static int debug_got_console = 0;
 
 static void dputs(char *buf)
@@ -599,15 +600,18 @@ static void dputs(char *buf)
     DWORD dw;
 
     if (!debug_got_console) {
-	AllocConsole();
-	debug_got_console = 1;
+	if (AllocConsole()) {
+	    debug_got_console = 1;
+	    debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
+	}
     }
     if (!debug_fp) {
 	debug_fp = fopen("debug.log", "w");
     }
 
-    WriteFile(GetStdHandle(STD_OUTPUT_HANDLE), buf, strlen(buf), &dw,
-	      NULL);
+    if (debug_hdl != INVALID_HANDLE_VALUE) {
+	WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
+    }
     fputs(buf, debug_fp);
     fflush(debug_fp);
 }