Hi,
I've just found range() behaves unexpectedly in some special cases.
For instance, please try the following script.
<?php
echo count(range('a', 'z', 12));
?>
will give 45 while it should return an array that consists of 3 elements.
That is because the counting may exceed the upper limit of positive char
value during the loop.
The attached patch is a fix for this issue. I'll commit this if there are
no objections.
Moriyoshi
Index: ext/standard/array.c
===================================================================
RCS file: /repository/php4/ext/standard/array.c,v
retrieving revision 1.201
diff -u -r1.201 array.c
--- ext/standard/array.c 15 Nov 2002 02:16:41 -0000 1.201
+++ ext/standard/array.c 23 Nov 2002 06:20:16 -0000
@@ -1435,19 +1435,29 @@
/* If the range is given as strings, generate an array of characters. */
if (Z_TYPE_P(zlow) == IS_STRING && Z_TYPE_P(zhigh) == IS_STRING) {
- char *low, *high;
+ unsigned char *low, *high;
convert_to_string_ex(&zlow);
convert_to_string_ex(&zhigh);
- low = Z_STRVAL_P(zlow);
- high = Z_STRVAL_P(zhigh);
+ low = (unsigned char *)Z_STRVAL_P(zlow);
+ high = (unsigned char *)Z_STRVAL_P(zhigh);
if (*low > *high) { /* Negative steps */
- for (; *low >= *high; (*low) -= step) {
+ if (*low - *high < step || step < 0) {
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "step
+exceeds the specified range");
+ zval_dtor(return_value);
+ RETURN_FALSE;
+ }
+ for (; *low >= *high; (*low) -= (unsigned int)step) {
add_next_index_stringl(return_value, low, 1, 1);
}
} else { /* Positive steps */
- for (; *low <= *high; (*low) += step) {
+ if (*high - *low < step || step < 0) {
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "step
+exceeds the specified range");
+ zval_dtor(return_value);
+ RETURN_FALSE;
+ }
+ for (; *low <= *high; (*low) += (unsigned int)step) {
add_next_index_stringl(return_value, low, 1, 1);
}
}
@@ -1460,10 +1470,20 @@
high = Z_LVAL_P(zhigh);
if (low > high) { /* Negative steps */
+ if (low - high < step || step < 0) {
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "step
+exceeds the specified range");
+ zval_dtor(return_value);
+ RETURN_FALSE;
+ }
for (; low >= high; low -= step) {
add_next_index_long(return_value, low);
}
} else { /* Positive steps */
+ if (high - low < step || step < 0) {
+ php_error_docref(NULL TSRMLS_CC, E_WARNING, "step
+exceeds the specified range");
+ zval_dtor(return_value);
+ RETURN_FALSE;
+ }
for (; low <= high; low += step) {
add_next_index_long(return_value, low);
}
--
PHP Development Mailing List <http://www.php.net/>
To unsubscribe, visit: http://www.php.net/unsub.php
