Support conjunctive keyword search in RPC interface

Newly supported API Version 6 modifies `type=search` for _by_ type
`name-desc`: it now behaves the same as `name-desc` search through the
https://aur.archlinux.org/packages/ search page.

Search for packages containing the literal keyword `blah blah` AND `haha`:
https://aur.archlinux.org/rpc/?v=6&type=search&arg="blah blah"%20haha

Search for packages containing the literal keyword `abc 123`:
https://aur.archlinux.org/rpc/?v=6&type=search&arg="abc 123"

The following example searches for packages that contain `blah` AND `abc`:
https://aur.archlinux.org/rpc/?v=6&type=search&arg=blah%20abc

The legacy method still searches for packages that contain `blah abc`:
https://aur.archlinux.org/rpc/?v=5&type=search&arg=blah%20abc
https://aur.archlinux.org/rpc/?v=5&type=search&arg=blah%20abc

API Version 6 is currently only considered during a `search` of `name-desc`.

Note: This change was written as a solution to
https://bugs.archlinux.org/task/49133

.

PS: + Some spacing issues fixed in comments.

Signed-off-by: Kevin Morris <kevr.gtalk@gmail.com>
Signed-off-by: Lukas Fleischer <lfleischer@archlinux.org>

doc/rpc.txt

@@ -39,6 +39,10 @@ Examples
   `/rpc/?v=5&type=search&by=makedepends&arg=boost`
 `search` with callback::
   `/rpc/?v=5&type=search&arg=foobar&callback=jsonp1192244621103`
+`search` with API Version 6 for packages containing `cookie` AND `milk`::
+  `/rpc/?v=6&type=search&arg=cookie%20milk`
+`search` with API Version 6 for packages containing `cookie milk`::
+  `/rpc/?v=6&type=search&arg="cookie milk"`
 `info`::
   `/rpc/?v=5&type=info&arg[]=foobar`
 `info` with multiple packages::

web/lib/aurjson.class.php

 <?php
 
 include_once("aur.inc.php");
+include_once("pkgfuncs.inc.php");
 
 /*
  * This class defines a remote interface for fetching data from the AUR using
@@ -80,7 +81,7 @@ class AurJSON {
 		if (isset($http_data['v'])) {
 			$this->version = intval($http_data['v']);
 		}
-		if ($this->version < 1 || $this->version > 5) {
+		if ($this->version < 1 || $this->version > 6) {
 			return $this->json_error('Invalid version specified.');
 		}
 
@@ -140,7 +141,7 @@ class AurJSON {
 	}
 
 	/*
-	 * Check if an IP needs to be  rate limited.
+	 * Check if an IP needs to be rate limited.
 	 *
 	 * @param $ip IP of the current request
 	 *
@@ -192,7 +193,7 @@ class AurJSON {
 		$value = get_cache_value('ratelimit-ws:' . $ip, $status);
 		if (!$status || ($status && $value < $deletion_time)) {
 			if (set_cache_value('ratelimit-ws:' . $ip, $time, $window_length) &&
-			    set_cache_value('ratelimit:' . $ip, 1, $window_length)) {
+				set_cache_value('ratelimit:' . $ip, 1, $window_length)) {
 				return;
 			}
 		} else {
@@ -370,7 +371,7 @@ class AurJSON {
 		} elseif ($this->version >= 2) {
 			if ($this->version == 2 || $this->version == 3) {
 				$fields = implode(',', self::$fields_v2);
-			} else if ($this->version == 4 || $this->version == 5) {
+			} else if ($this->version >= 4 && $this->version <= 6) {
 				$fields = implode(',', self::$fields_v4);
 			}
 			$query = "SELECT {$fields} " .
@@ -492,13 +493,21 @@ class AurJSON {
 			if (strlen($keyword_string) < 2) {
 				return $this->json_error('Query arg too small.');
 			}
-			$keyword_string = $this->dbh->quote("%" . addcslashes($keyword_string, '%_') . "%");
 
-			if ($search_by === 'name') {
-				$where_condition = "(Packages.Name LIKE $keyword_string)";
-			} else if ($search_by === 'name-desc') {
-				$where_condition = "(Packages.Name LIKE $keyword_string OR ";
-				$where_condition .= "Description LIKE $keyword_string)";
+			if ($this->version >= 6 && $search_by === 'name-desc') {
+				$where_condition = construct_keyword_search($this->dbh,
+					$keyword_string, true, false);
+			} else {
+				$keyword_string = $this->dbh->quote(
+					"%" . addcslashes($keyword_string, '%_') . "%");
+
+				if ($search_by === 'name') {
+					$where_condition = "(Packages.Name LIKE $keyword_string)";
+				} else if ($search_by === 'name-desc') {
+					$where_condition = "(Packages.Name LIKE $keyword_string ";
+					$where_condition .= "OR Description LIKE $keyword_string)";
+				}
+
 			}
 		} else if ($search_by === 'maintainer') {
 			if (empty($keyword_string)) {

web/lib/pkgfuncs.inc.php

@@ -696,8 +696,10 @@ function pkg_search_page($params, $show_headers=true, $SID="") {
 			$q_where .= "AND (PackageBases.Name LIKE " . $dbh->quote($K) . ") ";
 		}
 		elseif (isset($params["SeB"]) && $params["SeB"] == "k") {
-			/* Search by keywords. */
-			$q_where .= construct_keyword_search($dbh, $params['K'], false);
+			/* Search by name. */
+			$q_where .= "AND (";
+			$q_where .= construct_keyword_search($dbh, $params['K'], false, true);
+			$q_where .= ") ";
 		}
 		elseif (isset($params["SeB"]) && $params["SeB"] == "N") {
 			/* Search by name (exact match). */
@@ -709,7 +711,9 @@ function pkg_search_page($params, $show_headers=true, $SID="") {
 		}
 		else {
 			/* Keyword search (default). */
-			$q_where .= construct_keyword_search($dbh, $params['K'], true);
+			$q_where .= "AND (";
+			$q_where .= construct_keyword_search($dbh, $params['K'], true, true);
+			$q_where .= ") ";
 		}
 	}
 
@@ -832,10 +836,11 @@ function pkg_search_page($params, $show_headers=true, $SID="") {
  * @param handle $dbh Database handle
  * @param string $keywords The search term
  * @param bool $namedesc Search name and description fields
+ * @param bool $keyword Search packages with a matching PackageBases.Keyword
  *
  * @return string WHERE part of the SQL clause
  */
-function construct_keyword_search($dbh, $keywords, $namedesc) {
+function construct_keyword_search($dbh, $keywords, $namedesc, $keyword=false) {
 	$count = 0;
 	$where_part = "";
 	$q_keywords = "";
@@ -860,13 +865,18 @@ function construct_keyword_search($dbh, $keywords, $namedesc) {
 
 		$term = "%" . addcslashes($term, '%_') . "%";
 		$q_keywords .= $op . " (";
+		$q_keywords .= "Packages.Name LIKE " . $dbh->quote($term) . " ";
 		if ($namedesc) {
-			$q_keywords .= "Packages.Name LIKE " . $dbh->quote($term) . " OR ";
-			$q_keywords .= "Description LIKE " . $dbh->quote($term) . " OR ";
+			$q_keywords .= "OR Description LIKE " . $dbh->quote($term) . " ";
+		}
+
+		if ($keyword) {
+			$q_keywords .= "OR EXISTS (SELECT * FROM PackageKeywords WHERE ";
+			$q_keywords .= "PackageKeywords.PackageBaseID = Packages.PackageBaseID AND ";
+			$q_keywords .= "PackageKeywords.Keyword LIKE " . $dbh->quote($term) . ")) ";
+		} else {
+			$q_keywords .= ") ";
 		}
-		$q_keywords .= "EXISTS (SELECT * FROM PackageKeywords WHERE ";
-		$q_keywords .= "PackageKeywords.PackageBaseID = Packages.PackageBaseID AND ";
-		$q_keywords .= "PackageKeywords.Keyword LIKE " . $dbh->quote($term) . ")) ";
 
 		$count++;
 		if ($count >= 20) {
@@ -875,11 +885,7 @@ function construct_keyword_search($dbh, $keywords, $namedesc) {
 		$op = "AND ";
 	}
 
-	if (!empty($q_keywords)) {
-		$where_part = "AND (" . $q_keywords . ") ";
-	}
-
-	return $where_part;
+	return $q_keywords;
 }
 
 /**