logging: fix signed vs. unsigned cmp warning

diff --git a/usual/logging.c b/usual/logging.c
index 223753174a2c5db880df3cc8ad42482812e0815a..36e34e48433cddb3dc40ceb19bcde46f5dbd8afe 100644 (file)
--- a/usual/logging.c
+++ b/usual/logging.c
@@ -106,6 +106,8 @@ void log_generic(enum LogLevel level, void *ctx, const char *fmt, ...)
                pfxlen = logging_prefix_cb(level, ctx, buf, sizeof(buf));
                if (pfxlen < 0)
                        return;
+               if (pfxlen >= (int)sizeof(buf))
+                       pfxlen = sizeof(buf) - 1;
        }
        va_start(ap, fmt);
        vsnprintf(buf + pfxlen, sizeof(buf) - pfxlen, fmt, ap);