ext/standard: Add some sscanf tests

This is in preparation for some major refactoring as the current error messages are non-sensical

Author: Girgias

ext/standard/tests/strings/scanf/sscanf_binary_strings.phpt

@@ -0,0 +1,25 @@
+--TEST--
+sscanf(): with strings containing null bytes
+--FILE--
+<?php
+
+$str = "Hello\0wonderful\0World!";
+$format = "%s\0%s\0%s";
+try {
+    var_dump(sscanf($str, $format));
+} catch (Throwable $e) {
+    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+}
+try {
+    var_dump(sscanf($str, $format, $a, $b, $c));
+    var_dump($a, $b, $c);
+} catch (Throwable $e) {
+    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+}
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  string(5) "Hello"
+}
+ValueError: Variable is not assigned by any conversion specifiers

ext/standard/tests/strings/scanf/sscanf_format_string_XPG_assignments.phpt

@@ -0,0 +1,47 @@
+--TEST--
+sscanf(): format string XPG argument tests
+--FILE--
+<?php
+
+
+$formats = [
+	'%1$s %2$s %1$s',
+	'%1$s %*s %3$s',
+	'%s %*s %3$s',
+];
+
+$str = "Hello World";
+
+foreach ($formats as $format) {
+	echo "Using format string '$format':\n";
+	try {
+	    var_dump(sscanf($str, $format));
+	} catch (Throwable $e) {
+	    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+	}
+	try {
+	    var_dump(sscanf($str, $format, $a, $b, $c));
+	    var_dump($a, $b, $c);
+	    $a = $b = $c = null;
+	} catch (Throwable $e) {
+	    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+	}
+}
+?>
+--EXPECT--
+Using format string '%1$s %2$s %1$s':
+ValueError: Variable is assigned by multiple "%n$" conversion specifiers
+ValueError: Variable is assigned by multiple "%n$" conversion specifiers
+Using format string '%1$s %*s %3$s':
+array(3) {
+  [0]=>
+  string(5) "Hello"
+  [1]=>
+  NULL
+  [2]=>
+  NULL
+}
+ValueError: Variable is not assigned by any conversion specifiers
+Using format string '%s %*s %3$s':
+ValueError: cannot mix "%" and "%n$" conversion specifiers
+ValueError: cannot mix "%" and "%n$" conversion specifiers

ext/standard/tests/strings/scanf/sscanf_format_string_unterminated_rangespecifier.phpt

@@ -0,0 +1,45 @@
+--TEST--
+sscanf(): unterminated range [] specifier
+--FILE--
+<?php
+
+function combinatorial_concat(string $base, array $patterns): array {
+	$r = [$base];
+	foreach ($patterns as $pattern) {
+		$r = array_merge(
+			...array_map(
+				fn (string $str) => [$str, $str . $pattern],
+				$r,
+			)
+		);
+	}
+	return $r;
+}
+
+$modifiers = [
+	'^',
+	']',
+];
+
+$formats = combinatorial_concat('%[', $modifiers);
+
+$str = "Hello World";
+
+foreach ($formats as $format) {
+	echo "Using format string '$format':\n";
+	try {
+	    sscanf($str, $format);
+	} catch (Throwable $e) {
+	    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+	}
+}
+?>
+--EXPECT--
+Using format string '%[':
+ValueError: Unmatched [ in format string
+Using format string '%[]':
+ValueError: Unmatched [ in format string
+Using format string '%[^':
+ValueError: Unmatched [ in format string
+Using format string '%[^]':
+ValueError: Unmatched [ in format string

ext/standard/tests/strings/scanf/sscanf_format_string_unterminated_specifier.phpt

@@ -0,0 +1,71 @@
+--TEST--
+sscanf(): format string which is unterminated
+--FILE--
+<?php
+
+function combinatorial_concat(string $base, array $patterns): array {
+	$r = [$base];
+	foreach ($patterns as $pattern) {
+		$r = array_merge(
+			...array_map(
+				fn (string $str) => [$str, $str . $pattern],
+				$r,
+			)
+		);
+	}
+	return $r;
+}
+
+$modifiers = [
+	'*',
+	'1$', // XPG
+	'2', // Width
+	'L', // Size
+];
+
+$formats = combinatorial_concat('%', $modifiers);
+
+$str = "Hello World";
+
+foreach ($formats as $format) {
+	echo "Using format string '$format':\n";
+	try {
+	    sscanf($str, $format);
+	} catch (Throwable $e) {
+	    echo $e::class, ': ', $e->getMessage(), PHP_EOL;
+	}
+}
+?>
+--EXPECT--
+Using format string '%':
+ValueError: Bad scan conversion character "
+Using format string '%L':
+ValueError: Bad scan conversion character "
+Using format string '%2':
+ValueError: Bad scan conversion character "
+Using format string '%2L':
+ValueError: Bad scan conversion character "
+Using format string '%1$':
+ValueError: Bad scan conversion character "
+Using format string '%1$L':
+ValueError: Bad scan conversion character "
+Using format string '%1$2':
+ValueError: Bad scan conversion character "
+Using format string '%1$2L':
+ValueError: Bad scan conversion character "
+Using format string '%*':
+ValueError: Bad scan conversion character "
+Using format string '%*L':
+ValueError: Bad scan conversion character "
+Using format string '%*2':
+ValueError: Bad scan conversion character "
+Using format string '%*2L':
+ValueError: Bad scan conversion character "
+Using format string '%*1$':
+ValueError: Bad scan conversion character "$"
+Using format string '%*1$L':
+ValueError: Bad scan conversion character "$"
+Using format string '%*1$2':
+ValueError: Bad scan conversion character "$"
+Using format string '%*1$2L':
+ValueError: Bad scan conversion character "$"