fix return value of wmemcmp for extreme wchar_t values

[musl] / src / string / strstr.c

diff --git a/src/string/strstr.c b/src/string/strstr.c
index 683cdd0..96657bc 100644 (file)
--- a/src/string/strstr.c
+++ b/src/string/strstr.c
@@ -1,5 +1,4 @@
 #include <string.h>
-#include <stdlib.h>
 #include <stdint.h>
 
 static char *twobyte_strstr(const unsigned char *h, const unsigned char *n)
@@ -11,30 +10,20 @@ static char *twobyte_strstr(const unsigned char *h, const unsigned char *n)
 
 static char *threebyte_strstr(const unsigned char *h, const unsigned char *n)
 {
-       uint32_t nw = n[0]<<24 | n[1]<<16 | n[2]<<8;
-       uint32_t hw = h[0]<<24 | h[1]<<16 | h[2]<<8;
+       uint32_t nw = (uint32_t)n[0]<<24 | n[1]<<16 | n[2]<<8;
+       uint32_t hw = (uint32_t)h[0]<<24 | h[1]<<16 | h[2]<<8;
        for (h+=2; *h && hw != nw; hw = (hw|*++h)<<8);
        return *h ? (char *)h-2 : 0;
 }
 
 static char *fourbyte_strstr(const unsigned char *h, const unsigned char *n)
 {
-       uint32_t nw = n[0]<<24 | n[1]<<16 | n[2]<<8 | n[3];
-       uint32_t hw = h[0]<<24 | h[1]<<16 | h[2]<<8 | h[3];
+       uint32_t nw = (uint32_t)n[0]<<24 | n[1]<<16 | n[2]<<8 | n[3];
+       uint32_t hw = (uint32_t)h[0]<<24 | h[1]<<16 | h[2]<<8 | h[3];
        for (h+=3; *h && hw != nw; hw = hw<<8 | *++h);
        return *h ? (char *)h-3 : 0;
 }
 
-#if 0
-static char *naive_strstr(const char *h, const char *n)
-{
-       size_t i;
-       for (i=0; n[i] && h[i]; i++)
-       for (   ; n[i] != h[i]; h++, i=0);
-       return n[i] ? 0 : (char *)h;
-}
-#endif
-
 #define MAX(a,b) ((a)>(b)?(a):(b))
 #define MIN(a,b) ((a)<(b)?(a):(b))
 
@@ -107,7 +96,7 @@ static char *twoway_strstr(const unsigned char *h, const unsigned char *n)
        for (;;) {
                /* Update incremental end-of-haystack pointer */
                if (z-h < l) {
-                       /* Fast estimate for MIN(l,63) */
+                       /* Fast estimate for MAX(l,63) */
                        size_t grow = l | 63;
                        const unsigned char *z2 = memchr(z, 0, grow);
                        if (z2) {
@@ -119,9 +108,8 @@ static char *twoway_strstr(const unsigned char *h, const unsigned char *n)
                /* Check last byte first; advance by shift on mismatch */
                if (BITOP(byteset, h[l-1], &)) {
                        k = l-shift[h[l-1]];
-                       //printf("adv by %zu (on %c) at [%s] (%zu;l=%zu)\n", k, h[l-1], h, shift[h[l-1]], l);
                        if (k) {
-                               if (mem0 && mem && k < p) k = l-p;
+                               if (k < mem) k = mem;
                                h += k;
                                mem = 0;
                                continue;
@@ -141,7 +129,7 @@ static char *twoway_strstr(const unsigned char *h, const unsigned char *n)
                }
                /* Compare left half */
                for (k=ms+1; k>mem && n[k-1] == h[k-1]; k--);
-               if (k == mem) return (char *)h;
+               if (k <= mem) return (char *)h;
                h += p;
                mem = mem0;
        }