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GirgiasGirgias
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Add str_decrement() function
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6 files changed

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‎ext/standard/basic_functions.stub.php

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@@ -2344,6 +2344,8 @@ function strtolower(string $string): string {}
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function str_increment(string $string): string {}
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function str_decrement(string $string): string {}
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/** @refcount 1 */
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function basename(string $path, string $suffix = ""): string {}
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‎ext/standard/basic_functions_arginfo.h

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‎ext/standard/string.c

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@@ -1246,6 +1246,51 @@ PHP_FUNCTION(str_increment)
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RETURN_STR(incremented);
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}
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PHP_FUNCTION(str_decrement)
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{
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zend_string *str;
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ZEND_PARSE_PARAMETERS_START(1, 1)
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Z_PARAM_STR(str)
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ZEND_PARSE_PARAMETERS_END();
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if (ZSTR_LEN(str) == 0) {
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zend_argument_value_error(1, "cannot be empty");
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RETURN_THROWS();
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}
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if (!zend_string_only_has_ascii_alphanumeric(str)) {
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zend_argument_value_error(1, "must be composed only of alphanumeric ASCII characters");
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RETURN_THROWS();
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}
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zend_string *decremented = zend_string_init(ZSTR_VAL(str), ZSTR_LEN(str), /* persistant */ false);
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size_t position = ZSTR_LEN(str)-1;
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bool carry = false;
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do {
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char c = ZSTR_VAL(decremented)[position];
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if (EXPECTED( (c > 'a' && c <= 'z') || (c > 'A' && c <= 'Z') || (c > '0' && c <= '9') )) {
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carry = false;
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ZSTR_VAL(decremented)[position]--;
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} else { /* if 'a', 'A', or '0' */
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carry = true;
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if (c == '0') {
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ZSTR_VAL(decremented)[position] = '9';
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} else {
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ZSTR_VAL(decremented)[position] += 25;
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}
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}
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} while (carry && position-- > 0);
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if (UNEXPECTED(carry)) {
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zend_string_release_ex(decremented, /* persistant */ false);
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zend_argument_value_error(1, "\"%s\" is out of decrement range", ZSTR_VAL(str));
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RETURN_THROWS();
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}
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RETURN_STR(decremented);
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}
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#if defined(PHP_WIN32)
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static bool _is_basename_start(const char *start, const char *pos)
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{

‎ext/standard/tests/strings/str_decrement_basic.phpt

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@@ -0,0 +1,54 @@
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--TEST--
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str_decrement(): Decrementing various strings
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--FILE--
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<?php
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$strictlyAlphaNumeric = [
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"Az",
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"aZ",
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"A9",
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"a9",
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// Carrying values until the beginning of the string (no underflow)
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"Za",
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"zA",
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"Z0",
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"z0",
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// string interpretable as a number in scientific notation
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"5e6",
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// Interned strings
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"d",
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"D",
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"4",
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];
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foreach ($strictlyAlphaNumeric as $s) {
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var_dump(str_decrement($s));
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var_dump($s);
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}
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?>
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--EXPECT--
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string(2) "Ay"
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string(2) "Az"
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string(2) "aY"
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string(2) "aZ"
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string(2) "A8"
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string(2) "A9"
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string(2) "a8"
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string(2) "a9"
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string(2) "Yz"
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string(2) "Za"
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string(2) "yZ"
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string(2) "zA"
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string(2) "Y9"
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string(2) "Z0"
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string(2) "y9"
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string(2) "z0"
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string(3) "5e5"
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string(3) "5e6"
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string(1) "c"
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string(1) "d"
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string(1) "C"
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string(1) "D"
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string(1) "3"
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string(1) "4"

‎ext/standard/tests/strings/str_decrement_errors.phpt

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--TEST--
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str_decrement(): Invalid strings to decrement should throw a ValueError
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--FILE--
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<?php
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$strings = [
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// Empty string
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"",
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// String increments are unaware of being "negative"
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"-cc",
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// Trailing whitespace
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"Z ",
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// Leading whitespace
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" Z",
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// Non-ASCII characters
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"é",
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"あいうえお",
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"α",
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"ω",
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"Α", // Capital alpha
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"Ω",
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// With period
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"foo1.txt",
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"1f.5",
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// With multiple period
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"foo.1.txt",
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"1.f.5",
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];
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foreach ($strings as $s) {
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try {
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var_dump(str_decrement($s));
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} catch (ValueError $e) {
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echo $e->getMessage(), PHP_EOL;
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}
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}
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?>
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--EXPECT--
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str_decrement(): Argument #1 ($string) cannot be empty
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters
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str_decrement(): Argument #1 ($string) must be composed only of alphanumeric ASCII characters

‎ext/standard/tests/strings/str_decrement_underflow.phpt

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--TEST--
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str_decrement(): Out of Range ValueErrors for strings that cannot be decremented
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--FILE--
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<?php
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$strings = [
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"0",
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"a",
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"A",
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"00",
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"Aa",
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"aA",
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"A0",
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"a0",
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"0a",
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"0A",
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];
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foreach ($strings as $s) {
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try {
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var_dump(str_decrement($s));
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} catch (ValueError $e) {
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echo $e->getMessage(), PHP_EOL;
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}
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}
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?>
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--EXPECT--
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str_decrement(): Argument #1 ($string) "0" is out of decrement range
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str_decrement(): Argument #1 ($string) "a" is out of decrement range
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str_decrement(): Argument #1 ($string) "A" is out of decrement range
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str_decrement(): Argument #1 ($string) "00" is out of decrement range
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str_decrement(): Argument #1 ($string) "Aa" is out of decrement range
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str_decrement(): Argument #1 ($string) "aA" is out of decrement range
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str_decrement(): Argument #1 ($string) "A0" is out of decrement range
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str_decrement(): Argument #1 ($string) "a0" is out of decrement range
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str_decrement(): Argument #1 ($string) "0a" is out of decrement range
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str_decrement(): Argument #1 ($string) "0A" is out of decrement range

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