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[re-adding bug-gnulib; this patch does not make sense for memmem.c, since
it no longer uses knuth_morris_pratt, but might still be useful for str-kmp.h]
- -------- Original Message --------
On Tue, 2008-01-08 at 11:15 +1100, Peter Miller wrote:
| Or am I missing something subtle?
yes, I was missing something subtle.
The attached patch adds comments to explain it to me.
Regards
Peter Miller <[EMAIL PROTECTED]>
/\/\* http://miller.emu.id.au/pmiller/
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- --
Don't work too hard, make some time for fun as well!
Eric Blake [EMAIL PROTECTED]
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--- memmem.c 2008-01-08 11:09:47.000000000 +1100
+++ new-memmem.c 2008-01-08 11:30:59.000000000 +1100
@@ -31,7 +31,9 @@
/* Knuth-Morris-Pratt algorithm.
See http://en.wikipedia.org/wiki/Knuth-Morris-Pratt_algorithm
- Return a boolean indicating success. */
+ Return a boolean indicating success: false means the malloc failed,
+ true means that the comparison has been completed, and *resultp will
+ the appropriate value to return from memmem. */
static bool
knuth_morris_pratt (const unsigned char *haystack,
@@ -148,6 +150,8 @@
}
freea (table);
+ /* The comparison has been completed, and *resultp now contains the
+ correct value to be returned from memmem. */
return true;
}
@@ -218,7 +222,10 @@
needle. */
if (comparison_count >= needle_len)
{
- /* Try the Knuth-Morris-Pratt algorithm. */
+ /* Try the Knuth-Morris-Pratt algorithm. Note that
+ returning false means the malloc failed, and we
+ will not try KMP again. Returning true means that
+ "result" contains the value to be returned my memmem. */
const unsigned char *result;
if (knuth_morris_pratt (haystack, last_haystack,
needle - 1, needle_len, &result))
