do NEVER unset $table or $db;

no need to test for isset() on $db and $table;
always test with strlen() for valid $table or $db;

db_datadict.php

@@ -31,7 +31,7 @@ PMA_checkParameters(array('db'));
 /**
  * Defines the url to return to in case of error in a sql statement
  */
-if (isset($table)) {
+if (strlen($table)) {
     $err_url = 'tbl_sql.php?' . PMA_generate_common_url($db, $table);
 } else {
     $err_url = 'db_sql.php?' . PMA_generate_common_url($db);

db_operations.php

@@ -22,7 +22,7 @@ require_once './libraries/mysql_charsets.lib.php';
 /**
  * Rename/move or copy database
  */
-if (isset($db) &&
+if (strlen($db) &&
     ((isset($db_rename) && $db_rename == 'true') ||
     (isset($db_copy) && $db_copy == 'true'))) {
 
@@ -340,7 +340,7 @@ if (!$is_information_schema) {
     // MySQL supports setting default charsets / collations for databases since
     // version 4.1.1.
         echo '<form method="post" action="./db_operations.php">' . "\n"
-           . PMA_generate_common_hidden_inputs($db, isset($table) ? $table : '')
+           . PMA_generate_common_hidden_inputs($db, $table)
            . '<fieldset>' . "\n"
            . '    <legend>';
         if ($cfg['PropertiesIconic']) {
@@ -372,7 +372,7 @@ if (!$is_information_schema) {
 
 
 // not sure about leaving the PDF dialog for information_schema
-if ($num_tables > 0 && isset($table)) {
+if ($num_tables > 0 && strlen($table)) {
     $takeaway = $url_query . '&amp;table=' . urlencode($table);
 } else {
     $takeaway = '';

index.php

@@ -73,9 +73,9 @@ foreach ($drops as $each_drop) {
 }
 unset($drops, $each_drop);
 
-if (! isset($GLOBALS['db']) || ! strlen($GLOBALS['db'])) {
+if (! strlen($GLOBALS['db'])) {
     $main_target = $GLOBALS['cfg']['DefaultTabServer'];
-} elseif (! isset($GLOBALS['table']) || ! strlen($GLOBALS['table'])) {
+} elseif (! strlen($GLOBALS['table'])) {
     $_GET['db'] = $GLOBALS['db'];
     $main_target = $GLOBALS['cfg']['DefaultTabDatabase'];
 } else {

libraries/auth/cookie.auth.lib.php

@@ -505,10 +505,10 @@ function PMA_auth_set_user()
 
         // any parameters to pass?
         $url_params = array();
-        if (isset($GLOBALS['db']) && strlen($GLOBALS['db'])) {
+        if (strlen($GLOBALS['db'])) {
             $url_params['db'] = $GLOBALS['db'];
         }
-        if (isset($GLOBALS['table']) && strlen($GLOBALS['table'])) {
+        if (strlen($GLOBALS['table'])) {
             $url_params['table'] = $GLOBALS['table'];
         }
         // Language change from the login panel needs to be remembered

libraries/common.lib.php

@@ -490,8 +490,8 @@ function PMA_mysqlDie($error_message = '', $the_query = '',
         if (strstr(strtolower($formatted_sql), 'select')) { // please show me help to the error on select
             echo PMA_showMySQLDocu('SQL-Syntax', 'SELECT');
         }
-        if ($is_modify_link && isset($db)) {
+        if ($is_modify_link && strlen($db)) {
-            if (isset($table)) {
+            if (strlen($table)) {
                 $doedit_goto = '<a href="tbl_sql.php?' . PMA_generate_common_url($db, $table) . '&amp;sql_query=' . urlencode($the_query) . '&amp;show_query=1">';
             } else {
                 $doedit_goto = '<a href="db_sql.php?' . PMA_generate_common_url($db) . '&amp;sql_query=' . urlencode($the_query) . '&amp;show_query=1">';
@@ -920,7 +920,7 @@ function PMA_reloadNavigation()
     // Reloads the navigation frame via JavaScript if required
     if (isset($GLOBALS['reload']) && $GLOBALS['reload']) {
         echo "\n";
-        $reload_url = './navigation.php?' . PMA_generate_common_url((isset($GLOBALS['db']) ? $GLOBALS['db'] : ''), '', '&');
+        $reload_url = './navigation.php?' . PMA_generate_common_url($GLOBALS['db'], '', '&');
         ?>
 <script type="text/javascript" language="javascript">
 //<![CDATA[
@@ -963,7 +963,7 @@ function PMA_showMessage($message, $sql_query = null)
 
     // Corrects the tooltip text via JS if required
     // @todo this is REALLY the wrong place to do this - very unexpected here
-    if ( isset($GLOBALS['table']) && strlen($GLOBALS['table']) && $cfg['ShowTooltip']) {
+    if (strlen($GLOBALS['table']) && $cfg['ShowTooltip']) {
         $result = PMA_DBI_try_query('SHOW TABLE STATUS FROM ' . PMA_backquote($GLOBALS['db']) . ' LIKE \'' . PMA_sqlAddslashes($GLOBALS['table'], true) . '\'');
         if ($result) {
             $tbl_status = PMA_DBI_fetch_assoc($result);
@@ -985,8 +985,8 @@ function PMA_showMessage($message, $sql_query = null)
     // Checks if the table needs to be repaired after a TRUNCATE query.
     // @todo this should only be done if isset($GLOBALS['sql_query']), what about $GLOBALS['display_query']???
     // @todo this is REALLY the wrong place to do this - very unexpected here
-    if (isset($GLOBALS['table']) && isset($GLOBALS['sql_query'])
+    if (strlen($GLOBALS['table']) && strlen($GLOBALS['sql_query'])
-        && $GLOBALS['sql_query'] == 'TRUNCATE TABLE ' . PMA_backquote($GLOBALS['table'])) {
+     && $GLOBALS['sql_query'] == 'TRUNCATE TABLE ' . PMA_backquote($GLOBALS['table'])) {
         if (!isset($tbl_status)) {
             $result = @PMA_DBI_try_query('SHOW TABLE STATUS FROM ' . PMA_backquote($GLOBALS['db']) . ' LIKE \'' . PMA_sqlAddslashes($GLOBALS['table'], true) . '\'');
             if ($result) {
@@ -1021,7 +1021,7 @@ function PMA_showMessage($message, $sql_query = null)
 
     if ($cfg['ShowSQL'] == true && ! empty($sql_query)) {
         // Basic url query part
-        $url_qpart = '?' . PMA_generate_common_url(isset($GLOBALS['db']) ? $GLOBALS['db'] : '', isset($GLOBALS['table']) ? $GLOBALS['table'] : '');
+        $url_qpart = '?' . PMA_generate_common_url($GLOBALS['db'], $GLOBALS['table']);
 
         // Html format the query to be displayed
         // The nl2br function isn't used because its result isn't a valid
@@ -1095,7 +1095,7 @@ function PMA_showMessage($message, $sql_query = null)
         // (don't go to default pages, we must go to the page
         // where the query box is available)
 
-        $edit_target = isset($GLOBALS['db']) ? (isset($GLOBALS['table']) ? 'tbl_sql.php' : 'db_sql.php') : 'server_sql.php';
+        $edit_target = strlen($GLOBALS['db']) ? (strlen($GLOBALS['table']) ? 'tbl_sql.php' : 'db_sql.php') : 'server_sql.php';
 
         if (isset($cfg['SQLQuery']['Edit'])
             && ($cfg['SQLQuery']['Edit'] == true)
@@ -1848,7 +1848,7 @@ function PMA_checkParameters($params, $die = true, $request = true)
  * @param   integer     $fields_cnt     number of fields
  * @param   array       $fields_meta    meta information about fields
  * @param   array       $row            current row
- * @param   boolean     $force_unique   generate condition only on pk or unique 
+ * @param   boolean     $force_unique   generate condition only on pk or unique
  *
  * @access  public
  * @author  Michal Cihar (michal@cihar.com)

libraries/db_common.inc.php

@@ -35,10 +35,10 @@ $err_url   = $cfg['DefaultTabDatabase'] . '?' . PMA_generate_common_url($db);
  */
 if (!isset($is_db) || !$is_db) {
     // Not a valid db name -> back to the welcome page
-    if (isset($db) && strlen($db)) {
+    if (strlen($db)) {
         $is_db = PMA_DBI_select_db($db);
     }
-    if (!isset($db) || !strlen($db) || !$is_db) {
+    if (! strlen($db) || !$is_db) {
         PMA_sendHeaderLocation($cfg['PmaAbsoluteUri'] . 'main.php?' . PMA_generate_common_url('', '', '&') . (isset($message) ? '&message=' . urlencode($message) : '') . '&reload=1');
         exit;
     }

libraries/db_table_exists.lib.php

@@ -11,7 +11,7 @@
  *
  */
 if (empty($is_db)) {
-    if (isset($db) && strlen($db)) {
+    if (strlen($db)) {
         $is_db = @PMA_DBI_select_db($db);
     } else {
         $is_db = false;
@@ -40,7 +40,7 @@ if (empty($is_db)) {
 
 if (empty($is_table) && !defined('PMA_SUBMIT_MULT')) {
     // Not a valid table name -> back to the db_sql.php
-    if (isset($table) && strlen($table)) {
+    if (strlen($table)) {
         $_result = PMA_DBI_try_query(
             'SHOW TABLES LIKE \'' . PMA_sqlAddslashes($table, true) . '\';',
             null, PMA_DBI_QUERY_STORE);
@@ -52,7 +52,7 @@ if (empty($is_table) && !defined('PMA_SUBMIT_MULT')) {
 
     if (! $is_table) {
         if (! defined('IS_TRANSFORMATION_WRAPPER')) {
-            if (isset($table) && strlen($table)) {
+            if (strlen($table)) {
                 // SHOW TABLES doesn't show temporary tables, so try select
                 // (as it can happen just in case temporary table, it should be
                 // fast):

libraries/display_export.lib.php

@@ -102,7 +102,7 @@ echo PMA_pluginGetJavascript($export_list);
 //]]>
 </script>
 
-<?php if ( isset($table) && strlen($table) && ! isset( $num_tables ) ) { ?>
+<?php if ( strlen($table) && ! isset( $num_tables ) ) { ?>
     <div class="formelementrow">
         <?php
         echo sprintf( $strDumpXRows,

libraries/display_select_lang.lib.php

@@ -37,11 +37,11 @@ function PMA_select_language($use_fieldset = FALSE) {
         echo '            <input type="hidden" name="convcharset" value="'
             . htmlspecialchars($GLOBALS['convcharset']) . '" />' . "\n";
     }
-    if (isset($GLOBALS['db'])) {
+    if (strlen($GLOBALS['db'])) {
         echo '            <input type="hidden" name="db" value="'
             . htmlspecialchars($GLOBALS['db']) . '" />' . "\n";
     }
-    if (isset($GLOBALS['table'])) {
+    if (strlen($GLOBALS['table'])) {
         echo '            <input type="hidden" name="table" value="'
             . htmlspecialchars($GLOBALS['table']) . '" />' . "\n";
     }

libraries/display_tbl.lib.php

@@ -170,7 +170,7 @@ function PMA_setDisplayMode(&$the_disp_mode, &$the_total)
     if (isset($unlim_num_rows) && $unlim_num_rows != '') {
         $the_total = $unlim_num_rows;
     } elseif (($do_display['nav_bar'] == '1' || $do_display['sort_lnk'] == '1')
-             && (isset($db) && strlen($db) && !empty($table))) {
+             && (strlen($db) && !empty($table))) {
         $the_total   = PMA_Table::countRecords($db, $table, true);
     }
 
@@ -1800,7 +1800,7 @@ function PMA_displayTable(&$dt_result, &$the_disp_mode, $analyzed_sql)
     }
 
     // 2.3 Displays the navigation bars
-    if (!isset($table) || strlen(trim($table)) == 0) {
+    if (! strlen($table)) {
         if (isset($analyzed_sql[0]['query_type'])
            && $analyzed_sql[0]['query_type'] == 'SELECT') {
             // table does not always contain a real table name,
@@ -1838,7 +1838,7 @@ function PMA_displayTable(&$dt_result, &$the_disp_mode, $analyzed_sql)
     $tabs    = '(\'' . join('\',\'', $target) . '\')';
 
     if ($cfgRelation['displaywork']) {
-        if (! isset($table) || ! strlen($table)) {
+        if (! strlen($table)) {
             $exist_rel = false;
         } else {
             $exist_rel = PMA_getForeigners($db, $table, '', 'both');

libraries/export/xml.php

@@ -9,7 +9,7 @@
 /**
  *
  */
-if (isset($GLOBALS['db']) && strlen($GLOBALS['db'])) { /* Can't do server export */
+if (strlen($GLOBALS['db'])) { /* Can't do server export */
 
 if (isset($plugin_list)) {
     $plugin_list['xml'] = array(

libraries/footer.inc.php

@@ -133,7 +133,7 @@ if (PMA_getenv('SCRIPT_NAME') && empty($_POST) && !$GLOBALS['checked_special'])
         . ' title="' . $GLOBALS['strOpenNewWindow'] . '" target="_blank">';
     /*
     echo '<a href="index.php?target=' . basename(PMA_getenv('SCRIPT_NAME'));
-    $url = PMA_generate_common_url(isset($GLOBALS['db']) ? $GLOBALS['db'] : '', isset($GLOBALS['table']) ? $GLOBALS['table'] : '');
+    $url = PMA_generate_common_url($GLOBALS['db'], $GLOBALS['table']);
     if (!empty($url)) {
         echo '&amp;' . $url;
     }

libraries/header.inc.php

@@ -42,8 +42,8 @@ if (empty($GLOBALS['is_header_sent'])) {
                         isset($GLOBALS['cfg']['Server']['host']) ? $GLOBALS['cfg']['Server']['host'] : '',
                         isset($GLOBALS['cfg']['Server']['verbose']) ? $GLOBALS['cfg']['Server']['verbose'] : '',
                         !empty($GLOBALS['cfg']['Server']['verbose']) ? $GLOBALS['cfg']['Server']['verbose'] : (isset($GLOBALS['cfg']['Server']['host']) ? $GLOBALS['cfg']['Server']['host'] : ''),
-                        isset($GLOBALS['db']) ? $GLOBALS['db'] : '',
+                        $GLOBALS['db'],
-                        isset($GLOBALS['table']) ? $GLOBALS['table'] : '',
+                        $GLOBALS['table'],
                         'phpMyAdmin ' . PMA_VERSION,
                         ),
                     !empty($GLOBALS['table']) ? $GLOBALS['cfg']['TitleTable'] :
@@ -200,7 +200,7 @@ if (empty($GLOBALS['is_header_sent'])) {
                 $GLOBALS['strServer'],
                 's_host.png' );
 
-        if (isset($GLOBALS['db']) && strlen($GLOBALS['db'])) {
+        if (strlen($GLOBALS['db'])) {
 
             echo $separator;
             printf( $item,
@@ -210,7 +210,7 @@ if (empty($GLOBALS['is_header_sent'])) {
                     $GLOBALS['strDatabase'],
                     's_db.png' );
 
-            if (isset($GLOBALS['table']) && strlen($GLOBALS['table'])) {
+            if (strlen($GLOBALS['table'])) {
                 require_once './libraries/tbl_info.inc.php';
 
                 echo $separator;

libraries/mult_submits.inc.php

@@ -128,11 +128,11 @@ if (!empty($submit_mult)
 if ( !empty($submit_mult) && !empty($what)) {
     $js_to_run = 'functions.js';
     unset($message);
-    if (isset($table) && strlen($table)) {
+    if (strlen($table)) {
         require('./libraries/tbl_common.php');
         $url_query .= '&goto=tbl_sql.php&back=tbl_sql.php';
         require('./libraries/tbl_info.inc.php');
-    } elseif (isset($db) && strlen($db)) {
+    } elseif (strlen($db)) {
         require('./libraries/db_common.inc.php');
         require('./libraries/db_info.inc.php');
     }

libraries/server_common.inc.php

@@ -28,7 +28,7 @@ if (empty($viewing_mode)) {
 /**
  * Set parameters for links
  */
-$url_query = PMA_generate_common_url((isset($db) ? $db : ''));
+$url_query = PMA_generate_common_url($db);
 
 /**
  * Defines the urls to return to in case of error in a sql statement

libraries/sql_query_form.lib.php

@@ -86,11 +86,11 @@ function PMA_sqlQueryForm($query = true, $display_tab = false, $delimiter = ';')
 
     $table  = '';
     $db     = '';
-    if (! isset($GLOBALS['db']) || ! strlen($GLOBALS['db'])) {
+    if (! strlen($GLOBALS['db'])) {
         // prepare for server related
         $goto   = empty($GLOBALS['goto']) ?
                     'server_sql.php' : $GLOBALS['goto'];
-    } elseif (! isset($GLOBALS['table']) || ! strlen($GLOBALS['table'])) {
+    } elseif (! strlen($GLOBALS['table'])) {
         // prepare for db related
         $db     = $GLOBALS['db'];
         $goto   = empty($GLOBALS['goto']) ?
@@ -218,12 +218,12 @@ function PMA_sqlQueryFormInsert($query = '', $is_querywindow = false, $delimiter
     $table          = '';
     $db             = '';
     $fields_list    = array();
-    if (! isset($GLOBALS['db']) || ! strlen($GLOBALS['db'])) {
+    if (! strlen($GLOBALS['db'])) {
         // prepare for server related
         $legend = sprintf($GLOBALS['strRunSQLQueryOnServer'],
             htmlspecialchars(
                 $GLOBALS['cfg']['Servers'][$GLOBALS['server']]['host']));
-    } elseif (! isset($GLOBALS['table']) || ! strlen($GLOBALS['table'])) {
+    } elseif (! strlen($GLOBALS['table'])) {
         // prepare for db related
         $db     = $GLOBALS['db'];
         // if you want navigation:
@@ -414,7 +414,7 @@ function PMA_sqlQueryFormInsert($query = '', $is_querywindow = false, $delimiter
  */
 function PMA_sqlQueryFormBookmark()
 {
-    $bookmark_list = PMA_listBookmarks(isset($GLOBALS['db']) ? $GLOBALS['db'] : '', $GLOBALS['cfg']['Bookmark'] );
+    $bookmark_list = PMA_listBookmarks($GLOBALS['db'], $GLOBALS['cfg']['Bookmark'] );
     if (! $bookmark_list || count($bookmark_list) < 1) {
         return;
     }

libraries/url_generating.lib.php

@@ -37,10 +37,10 @@ function PMA_generate_common_hidden_inputs($db = '', $table = '', $indent = 0, $
         $skip    =& $_skip;
     } else {
         $params = array();
-        if (isset($db) && strlen($db)) {
+        if (strlen($db)) {
             $params['db'] = $db;
         }
-        if (isset($table) && strlen($table)) {
+        if (strlen($table)) {
             $params['table'] = $table;
         }
     }
@@ -142,10 +142,10 @@ function PMA_generate_common_url ($db = '', $table = '', $delim = '&')
         $questionmark = '?';
     } else {
         $params = array();
-        if (isset($db) && strlen($db)) {
+        if (strlen($db)) {
             $params['db'] = $db;
         }
-        if (isset($table) && strlen($table)) {
+        if (strlen($table)) {
             $params['table'] = $table;
         }
         $questionmark = '';

main.php

@@ -18,12 +18,8 @@ if (!defined('PMA_DISPLAY_HEADING')) {
 require_once './libraries/common.inc.php';
 
 // Handles some variables that may have been sent by the calling script
-if (isset($db)) {
+$GLOBALS['db'] = '';
-    unset($db);
+$GLOBALS['table'] = '';
-}
-if (isset($table)) {
-    unset($table);
-}
 $show_query = '1';
 require_once './libraries/header.inc.php';
 

navigation.php

@@ -207,7 +207,7 @@ $href_left = '<a onclick="if (toggle(\'%d\')) return false;"'
 
 $element_counter = 0;
 
-if ($GLOBALS['cfg']['LeftFrameLight'] && isset($GLOBALS['db']) && strlen($GLOBALS['db'])) {
+if ($GLOBALS['cfg']['LeftFrameLight'] && strlen($GLOBALS['db'])) {
     // show selected databasename as link to DefaultTabDatabase-page
     // with table count in ()
     $common_url_query = PMA_generate_common_url($GLOBALS['db']);
@@ -477,13 +477,11 @@ function PMA_displayTableList($tables, $visible = false,
 
             $element_counter++;
             echo '<li>' . "\n";
-            if ($visible &&
+            if ($visible
-              ((isset($_REQUEST['tbl_group'])
+             && ((isset($_REQUEST['tbl_group'])
-                && (strpos($_REQUEST['tbl_group'], $group) === 0
+               && (strpos($_REQUEST['tbl_group'], $group) === 0
                 || strpos($_REQUEST['tbl_group'], $sep . $group) !== false))
-              ||
+              || strpos($GLOBALS['table'], $group) === 0)) {
-              (isset($GLOBALS['table'])
-                && strpos($GLOBALS['table'], $group) === 0))) {
                 printf($href_left, $element_counter,
                     $GLOBALS['common_url_query'] . '&amp;tbl_group=' . $tab_group_full);
                 printf($img_minus, $element_counter);
@@ -521,9 +519,7 @@ function PMA_displayTableList($tables, $visible = false,
               ((isset($_REQUEST['tbl_group'])
                 && (strpos($_REQUEST['tbl_group'], $group) === 0
                 || strpos($_REQUEST['tbl_group'], $sep . $group) !== false))
-              ||
+              || strpos($GLOBALS['table'], $group) === 0)) {
-              (isset($GLOBALS['table'])
-                && strpos($GLOBALS['table'], $group) === 0))) {
                 PMA_displayTableList($table, true,
                     $tab_group_full . $group, $table_db);
             } else {

sql.php

@@ -36,13 +36,13 @@ if (!empty($goto)) {
 } // end if (security checkings)
 
 if (empty($goto)) {
-    $goto = (! isset($table) || ! strlen($table)) ? $cfg['DefaultTabDatabase'] : $cfg['DefaultTabTable'];
+    $goto = (! strlen($table)) ? $cfg['DefaultTabDatabase'] : $cfg['DefaultTabTable'];
     $is_gotofile  = true;
 } // end if
 if (!isset($err_url)) {
     $err_url = (!empty($back) ? $back : $goto)
-             . '?' . PMA_generate_common_url(isset($db) ? $db : '')
+             . '?' . PMA_generate_common_url($db)
-             . ((strpos(' ' . $goto, 'db_') != 1 && isset($table)) ? '&table=' . urlencode($table) : '');
+             . ((strpos(' ' . $goto, 'db_') != 1 && strlen($table)) ? '&table=' . urlencode($table) : '');
 } // end if
 
 // Coming from a bookmark dialog
@@ -57,7 +57,7 @@ if (isset($fields['dbase'])) {
 
 // Default to browse if no query set an we have table
 // (needed for browsing from DefaultTabTable)
-if (! isset($sql_query) && isset($table) && isset($db)) {
+if (! isset($sql_query) && strlen($table) && strlen($db)) {
     require_once './libraries/bookmark.lib.php';
     $book_sql_query = PMA_queryBookmarks($db,
         $GLOBALS['cfg']['Bookmark'], '\'' . PMA_sqlAddslashes($table) . '\'',
@@ -158,8 +158,8 @@ if (isset($btnDrop) && $btnDrop == $strNo) {
         $goto = $back;
     }
     if ($is_gotofile) {
-        if (strpos(' ' . $goto, 'db_') == 1 && isset($table) && strlen($table)) {
+        if (strpos(' ' . $goto, 'db_') == 1 && strlen($table)) {
-            unset($table);
+            $table = '';
         }
         $active_page = $goto;
         require './' . PMA_securePath($goto);
@@ -197,7 +197,7 @@ if ($do_confirm) {
         echo '<h1 class="warning">' . $strDropDatabaseStrongWarning . '</h1>';
     }
     echo '<form action="sql.php" method="post">' . "\n"
-        .PMA_generate_common_hidden_inputs($db, (isset($table)?$table:''));
+        .PMA_generate_common_hidden_inputs($db, $table);
     ?>
     <input type="hidden" name="sql_query" value="<?php echo urlencode($sql_query); ?>" />
     <input type="hidden" name="zero_rows" value="<?php echo isset($zero_rows) ? PMA_sanitize($zero_rows) : ''; ?>" />
@@ -324,7 +324,7 @@ if (isset($pos)
     $full_sql_query      = $sql_query;
 } // end if...else
 
-if (isset($db)) {
+if (strlen($db)) {
     PMA_DBI_select_db($db);
 }
 
@@ -388,7 +388,7 @@ if (isset($GLOBALS['show_as_php']) || !empty($GLOBALS['validatequery'])) {
     // This could happen if the user sends a query like "USE `database`;"
     $res = PMA_DBI_query('SELECT DATABASE() AS \'db\';');
     $row = PMA_DBI_fetch_row($res);
-    if (isset($db) && is_array($row) && isset($row[0]) && (strcasecmp($db, $row[0]) != 0)) {
+    if (strlen($db) && is_array($row) && isset($row[0]) && (strcasecmp($db, $row[0]) != 0)) {
         $db     = $row[0];
         $reload = 1;
     }
@@ -561,9 +561,9 @@ if (isset($GLOBALS['show_as_php']) || !empty($GLOBALS['validatequery'])) {
     if (isset($purge) && $purge == '1') {
         require_once './libraries/relation_cleanup.lib.php';
 
-        if (isset($table) && isset($db) && strlen($table) && strlen($db)) {
+        if (strlen($table) && strlen($db)) {
             PMA_relationsCleanupTable($db, $table);
-        } elseif (isset($db) && strlen($db)) {
+        } elseif (strlen($db)) {
             PMA_relationsCleanupDatabase($db);
         } else {
             // garvin: VOID. No DB/Table gets deleted.
@@ -572,7 +572,6 @@ if (isset($GLOBALS['show_as_php']) || !empty($GLOBALS['validatequery'])) {
 
     // garvin: If a column gets dropped, do relation magic.
     if (isset($cpurge) && $cpurge == '1' && isset($purgekey)
-      && isset($db) && isset($table)
       && strlen($db) && strlen($table) && !empty($purgekey)) {
         require_once './libraries/relation_cleanup.lib.php';
         PMA_relationsCleanupColumn($db, $table, $purgekey);
@@ -628,14 +627,14 @@ if ($num_rows < 1 || $is_affected) {
         $is_db = $is_table = false;
         include 'libraries/db_table_exists.lib.php';
         if (strpos($goto, 'tbl_') === 0 && ! $is_table) {
-            if (isset($table)) {
+            if (strlen($table)) {
-                unset($table);
+                $table = '';
             }
             $goto = 'db_sql.php';
         }
         if (strpos($goto, 'db_') === 0 && ! $is_db) {
-            if (isset($db)) {
+            if (strlen($db)) {
-                unset($db);
+                $db = '';
             }
             $goto = 'main.php';
         }
@@ -666,12 +665,12 @@ else {
     } else {
         $js_to_run = 'functions.js';
         unset($message);
-        if (isset($table) && strlen($table)) {
+        if (strlen($table)) {
             require './libraries/tbl_common.php';
             $url_query .= '&amp;goto=tbl_sql.php&amp;back=tbl_sql.php';
             require './libraries/tbl_info.inc.php';
             require './libraries/tbl_links.inc.php';
-        } elseif (isset($db) && strlen($db)) {
+        } elseif (strlen($db)) {
             require './libraries/db_common.inc.php';
             require './libraries/db_info.inc.php';
         } else {
@@ -680,7 +679,7 @@ else {
         }
     }
 
-    if (isset($db) && strlen($db)) {
+    if (strlen($db)) {
         require_once './libraries/relation.lib.php';
         $cfgRelation = PMA_getRelationsParam();
     }
@@ -711,7 +710,7 @@ else {
     }
 
     // hide edit and delete links for information_schema
-    if (PMA_MYSQL_INT_VERSION >= 50002 && isset($db) && $db == 'information_schema') {
+    if (PMA_MYSQL_INT_VERSION >= 50002 && $db == 'information_schema') {
         $disp_mode = 'nnnn110111';
     }
 

tbl_indexes.php

@@ -19,10 +19,10 @@ require_once './libraries/tbl_indexes.lib.php';
  */
 if (!defined('PMA_IDX_INCLUDED')) {
     // Not a valid db name -> back to the welcome page
-    if ( isset($db) && strlen($db) ) {
+    if (strlen($db)) {
         $is_db = PMA_DBI_select_db($db);
     }
-    if ( !isset($db) || !strlen($db) || !$is_db ) {
+    if (!strlen($db) || !$is_db) {
         $uri_params = array( 'reload' => '1' );
         if ( isset($message) ) {
             $uri_params['message'] = $message;
@@ -32,11 +32,11 @@ if (!defined('PMA_IDX_INCLUDED')) {
         exit;
     }
     // Not a valid table name -> back to the default db sub-page
-    if ( isset($table) && strlen($table) ) {
+    if (strlen($table) ) {
         $is_table = PMA_DBI_query('SHOW TABLES LIKE \''
             . PMA_sqlAddslashes($table, TRUE) . '\'', null, PMA_DBI_QUERY_STORE);
     }
-    if ( ! isset($table) || ! strlen($table)
+    if (! strlen($table)
       || !( $is_table && PMA_DBI_num_rows($is_table) ) ) {
         $uri_params = array( 'reload' => '1', 'db' => $db );
         if ( isset($message) ) {

tbl_printview.php

@@ -38,7 +38,7 @@ $cfgRelation = PMA_getRelationsParam();
 /**
  * Defines the url to return to in case of error in a sql statement
  */
-if (isset($table)) {
+if (strlen($table)) {
     $err_url = 'tbl_sql.php?' . PMA_generate_common_url($db, $table);
 } else {
     $err_url = 'db_sql.php?' . PMA_generate_common_url($db);
@@ -57,7 +57,7 @@ PMA_DBI_select_db($db);
  */
 if (isset($selected_tbl) && is_array($selected_tbl)) {
     $the_tables   = $selected_tbl;
-} elseif (isset($table)) {
+} elseif (strlen($table)) {
     $the_tables[] = $table;
 }
 $multi_tables     = (count($the_tables) > 1);

tbl_replace.php

@@ -115,13 +115,13 @@ if (isset($_REQUEST['after_insert'])
     } else {
         $goto_include = $GLOBALS['goto'];
     }
-    if ($GLOBALS['goto'] == 'db_sql.php' && isset($GLOBALS['table'])) {
+    if ($GLOBALS['goto'] == 'db_sql.php' && strlen($GLOBALS['table'])) {
-        unset($GLOBALS['table']);
+        $GLOBALS['table'] = '';
     }
 }
 
 if (! $goto_include) {
-    if (! isset($GLOBALS['table']) || ! strlen($GLOBALS['table'])) {
+    if (! strlen($GLOBALS['table'])) {
         $goto_include = 'db_sql.php';
     } else {
         $goto_include = 'tbl_sql.php';