Add new snprintf/vsnprintf implementation. This should fix the compability

problems between Win32 (with its broken implementation) and the standard
stdio API.  Also fixed a bug in debug output where long messages got
truncated to 1023 chars, and in xmpp_stanza_to_text where long stanzas
got truncated by one character.

src/ctx.c

@@ -21,10 +21,6 @@
 #include "common.h"
 #include "util.h"
 
-#ifdef _WIN32
-#define vsnprintf _vsnprintf
-#endif
-
 /* initialization and shutdown */
 
 void xmpp_initialize(void)
@@ -142,11 +138,26 @@ void xmpp_log(const xmpp_ctx_t * const ctx,
 	      const char * const fmt,
 	      va_list ap)
 {
-    char buf[1024];
+    int oldret, ret;
+    char smbuf[1024];
+    char *buf;
 
-    /* FIXME: we don't send log lines > 1024 chars */
-
-    vsnprintf(buf, 1023, fmt, ap);
+    buf = smbuf;
+    ret = xmpp_vsnprintf(buf, 1023, fmt, ap);
+    if (ret > 1023) {
+	buf = (char *)xmpp_alloc(ctx, ret + 1);
+	if (!buf) {
+	    buf = NULL;
+	    xmpp_error(ctx, "log", "Failed allocating memory for log message.");
+	    return;
+	}
+	oldret = ret;
+	ret = xmpp_vsnprintf(buf, ret, fmt, ap);
+	if (ret > oldret) {
+	    xmpp_error(ctx, "log", "Unexpected error");
+	    return;
+	}
+    }
 
     if (ctx->log->handler)
         ctx->log->handler(ctx->log->userdata, level, area, buf);