Support named capturing groups in get_matches()

AF rules don't support associative arrays, so the named capturing groups are provided in the array only by their numeric keys.

Bug: T374294
Change-Id: I53b39917e6677f3a5b8f68bcf0faebf48668ea27

includes/Parser/FilterEvaluator.php

@@ -979,13 +979,18 @@ class FilterEvaluator {
 		// This way we can return a fixed-dimension array, much easier to manage.
 		// ToDo: Find a better way to do this.
 		// First, strip away escaped parentheses
-		$sanitized = preg_replace( '/(\\\\\\\\)*\\\\\(/', '', $needle );
+		$sanitized = preg_replace( '/((\\\\\\\\)*)\\\\\(/', '$1', $needle );
+
 		// Then strip starting parentheses of non-capturing groups, including
 		// atomics, lookaheads and so on, even if not every of them is supported.
-		$sanitized = str_replace( '(?', '', $sanitized );
+		// Avoid stripping named capturing groups: (?P<name>), (?<name>) and (?'name')
+		$sanitized = preg_replace( '/\(\?(?!P?<[a-zA-Z_][a-zA-Z0-9_]*>|\'[a-zA-Z_][a-zA-Z0-9_]*\')/', '', $sanitized );
+
 		// And also strip "(*", used with backtracking verbs like (*FAIL)
 		$sanitized = str_replace( '(*', '', $sanitized );
-		// Finally create an array of falses with dimension = # of capturing groups
+
+		// Finally create an array of falses with dimension = # of capturing groups + 1
+		// (as there is also the 0 element, which contains the whole match)
 		$groupscount = substr_count( $sanitized, '(' ) + 1;
 		$falsy = array_fill( 0, $groupscount, false );
 
@@ -1003,6 +1008,11 @@ class FilterEvaluator {
 			);
 		}
 
+		// Named capturing groups add the capture twice: with a numeric key and with a string key.
+		// AF doesn't provide associative arrays, thus we have to filter out the elements with string keys,
+		// else AFPData::newFromPHPVar would erroneously insert them into the final array, with numeric keys.
+		$matches = array_filter( $matches, 'is_int', ARRAY_FILTER_USE_KEY );
+
 		// Returned array has non-empty positions identical to the ones returned
 		// by the third parameter of a standard preg_match call ($matches in this case).
 		// We want an union with falsy to return a fixed-dimension array.

tests/parserTests/get-matches.t

@@ -2,4 +2,6 @@ get_matches('I am a (dog|cat)', 'What did you say?') === [ false, false ] &
 get_matches('The (truth|pineapple) is (?:rarely)? pure and (nee*v(ah|er) sh?imple)', 'The truth is rarely pure and never simple, Wilde said') == ['The truth is rarely pure and never simple', 'truth', 'never simple', 'er'] &
 get_matches('You say (.*) \(and I say (.*)\)\.', 'You say hello (and I say goodbye).') === [ 'You say hello (and I say goodbye).', 'hello', 'goodbye' ] &
 get_matches('I(?: am)? the ((walrus|egg man).*)\!', 'I am the egg man, I am the walrus !') === [ 'I am the egg man, I am the walrus !', 'egg man, I am the walrus ', 'egg man' ] &
-get_matches('this (does) not match', 'foo bar') === [ false, false ]
+get_matches('this (does) not match', 'foo bar') === [ false, false ] &
+get_matches('(?P<name1>foo) (?<name2>bar) (?\'name3\'baz)', 'foo bar baz') === [ 'foo bar baz', 'foo', 'bar', 'baz' ] &
+get_matches('(?P<name1>foo) (?<name2>bar) (?\'name3\'baz)', 'lorem ipsum') === [ false, false, false, false ]