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[PHP] Retain the next cautious URL match per mapping #589

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[PHP] Retain the next cautious URL match per mapping #589

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159 changes: 116 additions & 43 deletions ...url-rewrite/class-cautious-url-base-processor-in-text-with-mixed-unknown-escape-rules.php
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Original file line number Diff line number Diff line change
Expand Up @@ -122,6 +122,22 @@ class CautiousURLBaseProcessorInTextWithMixedUnknownEscapeRules {

private int $bytes_already_scanned = 0;

/**
* The next regex match already found for each mapping. A missing key has
* not been searched yet. A null value means that mapping has no later
* match in this text.
*
* @var array<int, array{
* scheme: array{0: string, 1: int},
* scheme_colon: array{0: string, 1: int},
* url_slash: array{0: string, 1: int},
* path_slash: array{0: string, 1: int},
* base: array{0: string, 1: int},
* authority: array{0: string, 1: int}
* }|null>
*/
private array $mapping_lookahead_matches = [];

/**
* @var array{
* source_authority: string,
Expand Down Expand Up @@ -284,61 +300,118 @@ public function get_updated_text(): string
*/
private function find_next_url_base(): ?array
{
$next_match = null;
foreach ($this->url_mappings as $mapping) {
$next_mapping = null;
$next_matches = null;
$next_authority_start = null;
if (count($this->url_mappings) === 1) {
// A single mapping advances after every match, leaving no future
// lookahead to reuse on the next call.
$next_mapping = $this->url_mappings[0];
$found = preg_match(
$mapping['pattern'],
$next_mapping['pattern'],
$this->text,
$matches,
$next_matches,
PREG_OFFSET_CAPTURE,
$this->bytes_already_scanned
);
if ($found !== 1) {
continue;
return null;
}

$authority_start = $matches['authority'][1];
if ($next_match !== null && $authority_start >= $next_match['start']) {
continue;
$next_authority_start = $next_matches['authority'][1];
} else {
foreach ($this->url_mappings as $mapping_index => $mapping) {
$has_lookahead = array_key_exists(
$mapping_index,
$this->mapping_lookahead_matches
);
$lookahead_matches = $has_lookahead
? $this->mapping_lookahead_matches[$mapping_index]
: null;
if (
!$has_lookahead
|| (
$lookahead_matches !== null
&& $lookahead_matches['authority'][1]
< $this->bytes_already_scanned
)
) {
$found = preg_match(
$mapping['pattern'],
$this->text,
$matches,
PREG_OFFSET_CAPTURE,
$this->bytes_already_scanned
);
$lookahead_matches = $found === 1
? [
'scheme' => $matches['scheme'],
'scheme_colon' => $matches['scheme_colon'],
'url_slash' => $matches['url_slash'],
'path_slash' => $matches['path_slash'] ?? ['', -1],
'base' => $matches['base'],
'authority' => $matches['authority'],
]
: null;
$this->mapping_lookahead_matches[$mapping_index] =
$lookahead_matches;
}

if ($lookahead_matches === null) {
continue;
}

$authority_start = $lookahead_matches['authority'][1];
if (
$next_authority_start !== null
&& $authority_start >= $next_authority_start
) {
continue;
}

$next_mapping = $mapping;
$next_matches = $lookahead_matches;
$next_authority_start = $authority_start;
}
}

$target_path_slash = '';
if ($mapping['target_path'] !== '') {
$target_path_slash = $matches['url_slash'][1] === -1
? $matches['path_slash'][0]
: $matches['url_slash'][0];
}
$target_port = '';
if ($mapping['target_port'] !== null) {
// No escaped colon is available here. Use an unescaped colon.
// This risks breaking an unknown format, but ':' is not a
// common string terminator in popular formats.
$target_port_colon = $matches['scheme_colon'][1] === -1
? ':'
: $matches['scheme_colon'][0];
$target_port = $target_port_colon . $mapping['target_port'];
}
if ($next_mapping === null || $next_matches === null) {
return null;
}

$next_match = array_merge(
$mapping,
[
'start' => $authority_start,
'base_length' => strlen($matches['base'][0]),
'replacement' => $mapping['target_domain'] . $target_port . str_replace(
'/',
$target_path_slash,
$mapping['target_path']
),
'scheme_start' => $matches['scheme'][1] === -1
? null
: $matches['scheme'][1],
'scheme_length' => strlen($matches['scheme'][0]),
'candidate_scheme' => strtolower($matches['scheme'][0]),
]
);
$target_path_slash = '';
if ($next_mapping['target_path'] !== '') {
$target_path_slash = $next_matches['url_slash'][1] === -1
? $next_matches['path_slash'][0]
: $next_matches['url_slash'][0];
}
$target_port = '';
if ($next_mapping['target_port'] !== null) {
// No escaped colon is available here. Use an unescaped colon.
// This risks breaking an unknown format, but ':' is not a
// common string terminator in popular formats.
$target_port_colon = $next_matches['scheme_colon'][1] === -1
? ':'
: $next_matches['scheme_colon'][0];
$target_port = $target_port_colon . $next_mapping['target_port'];
}

return $next_match;
return array_merge(
$next_mapping,
[
'start' => $next_authority_start,
'base_length' => strlen($next_matches['base'][0]),
'replacement' => $next_mapping['target_domain'] . $target_port . str_replace(
'/',
$target_path_slash,
$next_mapping['target_path']
),
'scheme_start' => $next_matches['scheme'][1] === -1
? null
: $next_matches['scheme'][1],
'scheme_length' => strlen($next_matches['scheme'][0]),
'candidate_scheme' => strtolower($next_matches['scheme'][0]),
]
);
}

/**
Expand Down
16 changes: 16 additions & 0 deletions tests/UrlRewriting/CautiousURLBaseProcessorInTextWithMixedUnknownEscapeRulesTest.php
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Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,22 @@ public static function supported_cases(): array
$eight_backslash_separator = str_repeat('\\', 8) . '/';

return [
'later mapping remains available while an earlier mapping repeats' => [
'https://one.example/a https://one.example/b https://two.example/c',
'https://destination-one.example/a https://destination-one.example/b https://destination-two.example/c',
[
'https://one.example' => 'https://destination-one.example',
'https://two.example' => 'https://destination-two.example',
],
],
'shorter overlapping mapping resumes after the longer match' => [
'https://source.example/media/a https://source.example/b',
'https://media.example/a https://root.example/b',
[
'https://source.example' => 'https://root.example',
'https://source.example/media' => 'https://media.example',
],
],
'unquoted CSS URL preserves its terminator' => [
'.hero{background-image:url(https://source.example/wp-content/uploads/2026/01/hero.jpg);}',
'.hero{background-image:url(https://destination.example/wp-content/uploads/2026/01/hero.jpg);}',
Expand Down
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