Fix issue with printing empty strings.

diff --git a/src/libutil/printf.c b/src/libutil/printf.c
index 0c4c8f03d0cd07e6c5402bf1273f827ec0a61e3a..195c045201cf63c14c07a1d61d6655a8e3138464 100644 (file)
--- a/src/libutil/printf.c
+++ b/src/libutil/printf.c
@@ -197,8 +197,12 @@ static glong
 rspamd_printf_append_file (const gchar *buf, glong buflen, gpointer ud)
 {
        FILE *dst = (FILE *)ud;
-
-       return fwrite (buf, 1, buflen, dst);
+       if (buflen > 0) {
+               return fwrite (buf, 1, buflen, dst);
+       }
+       else {
+               return 0;
+       }
 }
 
 static glong
@@ -206,7 +210,9 @@ rspamd_printf_append_gstring (const gchar *buf, glong buflen, gpointer ud)
 {
        GString *dst = (GString *)ud;
 
-       g_string_append_len (dst, buf, buflen);
+       if (buflen > 0) {
+               g_string_append_len (dst, buf, buflen);
+       }
 
        return buflen;
 }
@@ -296,7 +302,7 @@ rspamd_printf_gstring (GString *s, const gchar *fmt, ...)
 #define RSPAMD_PRINTF_APPEND(buf, len)                                                                                 \
     do {                                                                                                                                               \
     wr = func ((buf), (len), apd);                                                                                             \
-    if (wr <= 0) {                                                                                                                             \
+    if (wr < (__typeof(wr))(len)) {                                                                                    \
         goto oob;                                                                                                                              \
     }                                                                                                                                                  \
     written += wr;                                                                                                                             \
@@ -439,7 +445,6 @@ rspamd_vprintf_common (rspamd_printf_append_func func, gpointer apd, const gchar
                                        /* NULL terminated string */
                                        slen = strlen (p);
                                }
-
                                RSPAMD_PRINTF_APPEND (p, slen);
 
                                continue;