BUG/MEDIUM: channel: bad unlikely macro

The unlikely macro doesn't take in acount the condition, but only one
variable.

Must be backported in 1.6

[wt: with gcc 3.x, unlikely(x) is defined as __builtin_expect((x) != 0, 0)
 so the condition is wrong for negative numbers, which correspond to the
 case where bi_getblk_nc() has reached the end of the buffer and the
 channel is already closed. With gcc 4.x, the output is cast to unsigned long
 so the <=0 will not match negative values either. This is only used in Lua
 for now so that may explain why it hasn't hit yet]

diff --git a/src/channel.c b/src/channel.c
index 46921b856dc73a949bc1795ed191ca3012a441ca..fe65895c7ed19e116bb32d189c32ce97271a8f51 100644 (file)
--- a/src/channel.c
+++ b/src/channel.c
@@ -441,7 +441,7 @@ int bi_getline_nc(struct channel *chn,
        int l;
 
        retcode = bi_getblk_nc(chn, blk1, len1, blk2, len2);
-       if (unlikely(retcode) <= 0)
+       if (unlikely(retcode <= 0))
                return retcode;
 
        for (l = 0; l < *len1 && (*blk1)[l] != '\n'; l++);