Index: lib/dml/moodle_database.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/dml/moodle_database.php,v
retrieving revision 1.75
diff -u -r1.75 moodle_database.php
--- lib/dml/moodle_database.php	5 Dec 2008 00:10:27 -0000	1.75
+++ lib/dml/moodle_database.php	10 Dec 2008 10:00:25 -0000
@@ -420,6 +420,31 @@
     }
 
     /**
+     * Get the SQL condition for something containing, or not containing, a
+     * certain word. The generated SQL is only approximately right on DBs taht
+     * do not support regexps.
+     *
+     * @param string $searchterm the word we want to search for.
+     * @param bool $positivematch if true, return the operator for things matching the regexp, otherwise
+     *      return the operator for things not matching. Defaults to true.
+     * @param $placeholder the placeholder we want to use in this test.
+     * @return array with two elemnts, the SQL fragment and the parameter.
+     * 
+     * TODO may not work for non latin languages, but that is really up to DBs supporting [[:<:]] and [[:>:]] properly.
+     */
+    public function string_contains_word($searchterm, $positivematch = true, $placeholder = '?') {
+        if ($this->sql_regex_supported()) {
+            $param = '[[:<:]]' . preg_quote($searchterm, '|') . '[[:>:]]';
+            $test = $this->sql_regex(true) . ' ' . $placeholder;
+        } else {
+            // Do the best we can.
+            $param = '%' . $searchterm . '%'; // Should probably do something about % in $searchterm.
+            $test = $this->sql_ilike(true) . ' ' . $placeholder;
+        }
+        return array($test, $param);
+    }
+
+    /**
      * Converts short table name {tablename} to real table name
      * @param string sql
      * @return string sql
@@ -1493,10 +1518,16 @@
      * the caseinsensitive search using regexp_like() or NLS_COMP=LINGUISTIC :-(
      * See http://docs.moodle.org/en/XMLDB_Problems#Case-insensitive_searches
      *
-     * @return string
-     */
-    public function sql_ilike() {
-        return 'LIKE';
+     * @param bool $positivematch if true, return the operator for things matching the regexp, otherwise
+     *      return the operator for things not matching. Defaults to true.
+     * @return string the operator.
+     */
+    public function sql_ilike($positivematch = true) {
+        if ($positivematch) {
+            return 'LIKE';
+        } else {
+            return 'NOT LIKE';
+        }
     }
 
     /**
@@ -1659,8 +1690,9 @@
 
     /**
      * Return regex positive or negative match sql
-     * @param bool $positivematch
-     * @return string or empty if not supported
+     * @param bool $positivematch if true, return the operator for things matching the regexp, otherwise
+     *      return the operator for things not matching. Defaults to true.
+     * @return string the operator, or empty if not supported
      */
     public function sql_regex($positivematch=true) {
         return '';
Index: lib/datalib.php
===================================================================
RCS file: /cvsroot/moodle/moodle/lib/datalib.php,v
retrieving revision 1.493
diff -u -r1.493 datalib.php
--- lib/datalib.php	4 Dec 2008 08:53:11 -0000	1.493
+++ lib/datalib.php	10 Dec 2008 10:00:24 -0000
@@ -1003,50 +1003,30 @@
 function get_courses_search($searchterms, $sort='fullname ASC', $page=0, $recordsperpage=50, &$totalcount) {
     global $CFG, $DB;
 
-    if ($DB->sql_regex_supported()) {
-        $REGEXP    = $DB->sql_regex(true);
-        $NOTREGEXP = $DB->sql_regex(false);
-    }
-    $LIKE = $DB->sql_ilike(); // case-insensitive
-
     $searchcond = array();
-    $params     = array();
-    $i = 0;
+    $params = array();
+    $paramindex = 0;
 
     $concat = $DB->sql_concat('c.summary', "' '", 'c.fullname');
 
     foreach ($searchterms as $searchterm) {
-        $i++;
-
-        $NOT = ''; /// Initially we aren't going to perform NOT LIKE searches, only MSSQL and Oracle
-                   /// will use it to simulate the "-" operator with LIKE clause
-
-    /// Under Oracle and MSSQL, trim the + and - operators and perform
-    /// simpler LIKE (or NOT LIKE) queries
-        if (!$DB->sql_regex_supported()) {
-            if (substr($searchterm, 0, 1) == '-') {
-                $NOT = ' NOT ';
-            }
-            $searchterm = trim($searchterm, '+-');
-        }
-
-        // TODO: +- may not work for non latin languages
+        $paramindex++;
 
         if (substr($searchterm,0,1) == '+') {
             $searchterm = trim($searchterm, '+-');
-            $searchterm = preg_quote($searchterm, '|');
-            $searchcond[] = "$concat $REGEXP :ss$i";
-            $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
+            list($test, $param) = $DB->string_contains_word($searchterm, true, 'ss'.$paramindex);
+            $searchcond[] = $concat . ' ' . $test;
+            $params['ss'.$paramindex] = $param;
 
         } else if (substr($searchterm,0,1) == "-") {
             $searchterm = trim($searchterm, '+-');
-            $searchterm = preg_quote($searchterm, '|');
-            $searchcond[] = "$concat $NOTREGEXP :ss$i";
-            $params['ss'.$i] = "(^|[^a-zA-Z0-9])$searchterm([^a-zA-Z0-9]|$)";
+            list($test, $param) = $DB->string_contains_word($searchterm, false, 'ss'.$paramindex);
+            $searchcond[] = $concat . ' ' . $test;
+            $params['ss'.$paramindex] = $param;
 
         } else {
-            $searchcond[] = "$concat $NOT $LIKE :ss$i";
-            $params['ss'.$i] = "%$searchterm%";
+            $searchcond[] = $concat . ' ' . $DB->sql_ilike() . ':ss$paramindex';
+            $params['ss'.$paramindex] = "%$searchterm%";
         }
     }
 
@@ -1055,7 +1035,7 @@
         return array();
     }
 
-    $searchcond = implode(" AND ", $searchcond);
+    $searchcond = implode(' AND ', $searchcond);
 
     $sql = "SELECT c.*,
                    ctx.id AS ctxid, ctx.path AS ctxpath,
@@ -1066,31 +1046,29 @@
              WHERE $searchcond AND c.id <> ".SITEID."
           ORDER BY $sort";
     $courses = array();
-    $c = 0; // counts how many visible courses we've seen
+    $resultcount = 0; // counts how many visible courses we've seen
 
     if ($rs = $DB->get_recordset_sql($sql, $params)) {
-        // Tiki pagination
+        // Manual pagination, becuase it is too hard to do in SQL.
         $limitfrom = $page * $recordsperpage;
         $limitto   = $limitfrom + $recordsperpage;
 
         foreach($rs as $course) {
             $course = make_context_subobj($course);
             if ($course->visible || has_capability('moodle/course:viewhiddencourses', $course->context)) {
-                // Don't exit this loop till the end
-                // we need to count all the visible courses
-                // to update $totalcount
-                if ($c >= $limitfrom && $c < $limitto) {
+                // Don't exit this loop until the end. We need to count all the
+                // visible courses to update $totalcount
+                if ($resultcount >= $limitfrom && $resultcount < $limitto) {
                     $courses[$course->id] = $course;
                 }
-                $c++;
+                $resultcount += 1;
             }
         }
         $rs->close();
     }
 
-    // our caller expects 2 bits of data - our return
-    // array, and an updated $totalcount
-    $totalcount = $c;
+    // The caller expects 2 bits of data: the returned array and an updated $totalcount.
+    $totalcount = $resultcount;
     return $courses;
 }