diff --git a/lib/ddl/sql_generator.php b/lib/ddl/sql_generator.php
index 0555bf36988..dc6e1b7e40a 100644
--- a/lib/ddl/sql_generator.php
+++ b/lib/ddl/sql_generator.php
@@ -1086,40 +1086,19 @@ abstract class sql_generator {
             $name .= substr(trim($field),0,3);
         }
         // Prepend the prefix
-        $name = $this->prefix . $name;
+        $name = trim($this->prefix . $name);
 
-        $name = substr(trim($name), 0, $this->names_max_length - 1 - strlen($suffix)); //Max names_max_length
-
-        // Add the suffix
-        $namewithsuffix = $name;
-        if ($suffix) {
-            $namewithsuffix = $namewithsuffix . '_' . $suffix;
-        }
+        // Make sure name does not exceed the maximum name length and add suffix.
+        $maxlengthwithoutsuffix = $this->names_max_length - strlen($suffix) - ($suffix ? 1 : 0);
+        $namewithsuffix = substr($name, 0, $maxlengthwithoutsuffix) . ($suffix ? ('_' . $suffix) : '');
 
         // If the calculated name is in the cache, or if we detect it by introspecting the DB let's modify if
-        if (in_array($namewithsuffix, $used_names) || $this->isNameInUse($namewithsuffix, $suffix, $tablename)) {
-            $counter = 2;
-            // If have free space, we add 2
-            if (strlen($namewithsuffix) < $this->names_max_length) {
-                $newname = $name . $counter;
-            // Else replace the last char by 2
-            } else {
-                $newname = substr($name, 0, strlen($name)-1) . $counter;
-            }
-            $newnamewithsuffix = $newname;
-            if ($suffix) {
-                $newnamewithsuffix = $newnamewithsuffix . '_' . $suffix;
-            }
+        $counter = 1;
+        while (in_array($namewithsuffix, $used_names) || $this->isNameInUse($namewithsuffix, $suffix, $tablename)) {
             // Now iterate until not used name is found, incrementing the counter
-            while (in_array($newnamewithsuffix, $used_names) || $this->isNameInUse($newnamewithsuffix, $suffix, $tablename)) {
-                $counter++;
-                $newname = substr($name, 0, strlen($newname)-1) . $counter;
-                $newnamewithsuffix = $newname;
-                if ($suffix) {
-                    $newnamewithsuffix = $newnamewithsuffix . '_' . $suffix;
-                }
-            }
-            $namewithsuffix = $newnamewithsuffix;
+            $counter++;
+            $namewithsuffix = substr($name, 0, $maxlengthwithoutsuffix - strlen($counter)) .
+                    $counter . ($suffix ? ('_' . $suffix) : '');
         }
 
         // Add the name to the cache
diff --git a/lib/ddl/tests/ddl_test.php b/lib/ddl/tests/ddl_test.php
index c712880fa2d..7644a2319a1 100644
--- a/lib/ddl/tests/ddl_test.php
+++ b/lib/ddl/tests/ddl_test.php
@@ -1889,6 +1889,59 @@ class core_ddl_testcase extends database_driver_testcase {
         }
     }
 
+    public function test_object_name() {
+        $gen = $this->tdb->get_manager()->generator;
+
+        // This will form short object name and max length should not be exceeded.
+        $table = 'tablename';
+        $fields = 'id';
+        $suffix = 'pk';
+        for ($i=0; $i<12; $i++) {
+            $this->assertLessThanOrEqual($gen->names_max_length,
+                    strlen($gen->getNameForObject($table, $fields, $suffix)),
+                    'Generated object name is too long. $i = '.$i);
+        }
+
+        // This will form too long object name always and it must be trimmed to exactly 30 chars.
+        $table = 'aaaa_bbbb_cccc_dddd_eeee_ffff_gggg';
+        $fields = 'aaaaa,bbbbb,ccccc,ddddd';
+        $suffix = 'idx';
+        for ($i=0; $i<12; $i++) {
+            $this->assertEquals($gen->names_max_length,
+                    strlen($gen->getNameForObject($table, $fields, $suffix)),
+                    'Generated object name is too long. $i = '.$i);
+        }
+
+        // Same test without suffix.
+        $table = 'bbbb_cccc_dddd_eeee_ffff_gggg_hhhh';
+        $fields = 'aaaaa,bbbbb,ccccc,ddddd';
+        $suffix = '';
+        for ($i=0; $i<12; $i++) {
+            $this->assertEquals($gen->names_max_length,
+                    strlen($gen->getNameForObject($table, $fields, $suffix)),
+                    'Generated object name is too long. $i = '.$i);
+        }
+
+        // This must only trim name when counter is 10 or more.
+        $table = 'cccc_dddd_eeee_ffff_gggg_hhhh_iiii';
+        $fields = 'id';
+        $suffix = 'idx';
+        // Since we don't know how long prefix is, loop to generate tablename that gives exactly maxlengh-1 length.
+        // Skip this test if prefix is too long.
+        while (strlen($table) && strlen($gen->prefix.preg_replace('/_/','',$table).'_id_'.$suffix) >= $gen->names_max_length) {
+            $table = rtrim(substr($table, 0, strlen($table) - 1), '_');
+        }
+        if (strlen($table)) {
+            $this->assertEquals($gen->names_max_length - 1,
+                        strlen($gen->getNameForObject($table, $fields, $suffix)));
+            for ($i=0; $i<12; $i++) {
+                $this->assertEquals($gen->names_max_length,
+                        strlen($gen->getNameForObject($table, $fields, $suffix)),
+                        'Generated object name is too long. $i = '.$i);
+            }
+        }
+    }
+
     // Following methods are not supported == Do not test.
     /*
         public function testRenameIndex() {