Index: themes/tests/test_theme/test_theme.info
===================================================================
RCS file: /cvs/drupal/drupal/themes/tests/test_theme/test_theme.info,v
retrieving revision 1.1
diff -u -r1.1 test_theme.info
--- themes/tests/test_theme/test_theme.info	21 Mar 2010 04:05:24 -0000	1.1
+++ themes/tests/test_theme/test_theme.info	24 Apr 2010 10:08:35 -0000
@@ -3,4 +3,5 @@
 description = Theme for testing the theme system
 core = 7.x
 engine = phptemplate
-hidden = TRUE
\ No newline at end of file
+hidden = TRUE
+stylesheets-conditional[lte IE 8][all][] = ie.css
Index: modules/system/system.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/system/system.module,v
retrieving revision 1.922
diff -u -r1.922 system.module
--- modules/system/system.module	22 Apr 2010 07:36:50 -0000	1.922
+++ modules/system/system.module	24 Apr 2010 10:08:35 -0000
@@ -2369,6 +2369,17 @@
       }
     }
     $themes[$key]->info['stylesheets'] = $pathed_stylesheets;
+    $pathed_stylesheets_conditional = array();
+    if (isset($themes[$key]->info['stylesheets-conditional'])) {
+      foreach ($themes[$key]->info['stylesheets-conditional'] as $condition => $stylesheets_conditional) {
+        foreach ($stylesheets_conditional as $media => $stylesheets) {
+          foreach ($stylesheets as $stylesheet) {
+            $pathed_stylesheets_conditional[$condition][$media][$stylesheet] = dirname($themes[$key]->uri) . '/' . $stylesheet;
+          }
+        }
+      }
+    }
+    $themes[$key]->info['stylesheets-conditional'] = $pathed_stylesheets_conditional;
 
     // Give the scripts proper path information.
     $scripts = array();
Index: modules/simpletest/tests/common_test.module
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/common_test.module,v
retrieving revision 1.10
diff -u -r1.10 common_test.module
--- modules/simpletest/tests/common_test.module	2 Mar 2010 08:47:41 -0000	1.10
+++ modules/simpletest/tests/common_test.module	24 Apr 2010 10:08:34 -0000
@@ -41,6 +41,12 @@
     'access arguments' => array('access content'),
     'type' => MENU_CALLBACK,
   );
+  $items['conditional-styles'] = array(
+    'title' => 'Conditional styles test',
+    'page callback' => 'common_test_conditional_styles',
+    'access arguments' => array('access content'),
+    'type' => MENU_CALLBACK,
+  );
   return $items;
 }
 
@@ -198,3 +204,11 @@
    drupal_add_css(drupal_get_path('module', 'node') . '/node.css?arg1=value1&arg2=value2');
    return '';
 }
+
+/**
+ * Function to test 'browsers' option for drupal_add_css().
+ */
+function common_test_conditional_styles() {
+  drupal_add_css(drupal_get_path('module', 'simpletest') . '/simpletest.css', array('browsers' => array('IE' => 'lt IE 5', '!IE' => FALSE), 'preprocess' => FALSE));
+  return 'Add conditional style';
+}
Index: modules/simpletest/tests/common.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/common.test,v
retrieving revision 1.110
diff -u -r1.110 common.test
--- modules/simpletest/tests/common.test	22 Apr 2010 21:41:09 -0000	1.110
+++ modules/simpletest/tests/common.test	24 Apr 2010 10:08:34 -0000
@@ -699,6 +699,21 @@
     $query_string = substr(variable_get('css_js_query_string', '0'), 0, 1);
     $this->assertRaw(drupal_get_path('module', 'node') . '/node.css?arg1=value1&arg2=value2&' . $query_string, t('Query string was appended correctly to css.'));
   }
+
+  /**
+   * Test 'browsers' option in drupal_add_css().
+   */
+  function testConditionalStyles() {
+    // Create user with permission to access content.
+    $web_user = $this->drupalCreateUser(array('access content'));
+    $this->drupalLogin($web_user);
+    $this->drupalGet("conditional-styles");
+    $css = '<!--[if lt IE 5]>';
+    $this->assertRaw($css, t('Conditional stylesheets - condition exists.'));
+    $css = 'simpletest.css';
+    $this->assertRaw($css, t('Conditional stylesheets - drupal_add_css "browsers" option.'));
+  }
+
 }
 
 /**
Index: modules/simpletest/tests/theme.test
===================================================================
RCS file: /cvs/drupal/drupal/modules/simpletest/tests/theme.test,v
retrieving revision 1.15
diff -u -r1.15 theme.test
--- modules/simpletest/tests/theme.test	22 Apr 2010 22:33:29 -0000	1.15
+++ modules/simpletest/tests/theme.test	24 Apr 2010 10:08:34 -0000
@@ -66,6 +66,17 @@
     $_GET['q'] = $q;
     $this->assertTrue(in_array('page__front', $suggestions), t('Front page template was suggested.'));
   }
+  
+  /**
+   * Ensure conditional stylesheets are added.
+   */
+  function testThemeConditionalStylesheets() {
+    $this->drupalGet('theme-test/suggestion');
+    $css = '<!--[if lte IE 8]>';
+    $this->assertRaw($css, t('Conditional stylesheets in theme.info - condition exists'));
+    $css = 'ie.css';
+    $this->assertRaw($css, t('Conditional stylesheets in theme.info - file added'));
+  }
 }
 
 /**
Index: themes/garland/template.php
===================================================================
RCS file: /cvs/drupal/drupal/themes/garland/template.php,v
retrieving revision 1.39
diff -u -r1.39 template.php
--- themes/garland/template.php	4 Mar 2010 09:03:08 -0000	1.39
+++ themes/garland/template.php	24 Apr 2010 10:08:35 -0000
@@ -41,8 +41,6 @@
   if (theme_get_setting('garland_width') == 'fluid') {
     $vars['classes_array'][] = 'fluid-width';
   }
-  // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/fix-ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
 }
 
 /**
Index: themes/garland/garland.info
===================================================================
RCS file: /cvs/drupal/drupal/themes/garland/garland.info,v
retrieving revision 1.9
diff -u -r1.9 garland.info
--- themes/garland/garland.info	1 Dec 2009 15:57:40 -0000	1.9
+++ themes/garland/garland.info	24 Apr 2010 10:08:35 -0000
@@ -7,4 +7,5 @@
 engine = phptemplate
 stylesheets[all][] = style.css
 stylesheets[print][] = print.css
+stylesheets-conditional[lt IE 7][all][] = fix-ie.css
 settings[garland_width] = fluid
Index: includes/theme.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/theme.inc,v
retrieving revision 1.591
diff -u -r1.591 theme.inc
--- includes/theme.inc	23 Apr 2010 05:21:19 -0000	1.591
+++ includes/theme.inc	24 Apr 2010 10:08:33 -0000
@@ -140,6 +140,7 @@
   // We work it this way so that we can have child themes override parent
   // theme stylesheets easily.
   $final_stylesheets = array();
+  $final_stylesheets_conditional = array();
 
   // Grab stylesheets from base theme
   foreach ($base_theme as $base) {
@@ -150,6 +151,15 @@
         }
       }
     }
+    if (!empty($base->stylesheets_conditional)) {
+      foreach ($base->stylesheets_conditional as $condition => $stylesheets_conditional) {
+        foreach ($stylesheets_conditional as $media => $stylesheets) {
+          foreach ($stylesheets as $name => $stylesheet) {
+            $final_stylesheets_conditional[$condition][$media][$name] = $stylesheet;
+          }
+        }
+      }
+    }
   }
 
   // Add stylesheets used by this theme.
@@ -161,6 +171,17 @@
     }
   }
 
+  // Add conditional stylesheets used by this theme.
+  if (!empty($theme->stylesheets_conditional)) {
+    foreach ($theme->stylesheets_conditional as $condition => $stylesheets_conditional) {
+      foreach ($stylesheets_conditional as $media => $stylesheets) {
+        foreach ($stylesheets as $name => $stylesheet) {
+          $final_stylesheets_conditional[$condition][$media][$name] = $stylesheet;
+        }
+      }
+    }
+  }
+
   // And now add the stylesheets properly
   foreach ($final_stylesheets as $media => $stylesheets) {
     foreach ($stylesheets as $stylesheet) {
@@ -168,6 +189,15 @@
     }
   }
 
+  // And now add the conditional stylesheets properly
+  foreach ($final_stylesheets_conditional as $condition => $stylesheets_conditional) {
+    foreach ($stylesheets_conditional as $media => $stylesheets) {
+      foreach ($stylesheets as $name => $stylesheet) {
+        drupal_add_css($stylesheet, array('weight' => CSS_THEME, 'media' => $media, 'browsers' => array('IE' => $condition, '!IE' => FALSE), 'preprocess' => FALSE));
+      }
+    }
+  }
+
   // Do basically the same as the above for scripts
   $final_scripts = array();
 
@@ -597,6 +627,13 @@
           $theme->stylesheets[$media][$stylesheet] = $path;
         }
       }
+      foreach ($theme->info['stylesheets-conditional'] as $condition => $stylesheets_conditional) {
+        foreach ($stylesheets_conditional as $media => $stylesheets) {
+          foreach ($stylesheets as $stylesheet => $path) {
+            $theme->stylesheets_conditional[$condition][$media][$stylesheet] = $path;
+          }
+        }
+      }
       foreach ($theme->info['scripts'] as $script => $path) {
         if (file_exists($path)) {
           $theme->scripts[$script] = $path;
Index: themes/seven/template.php
===================================================================
RCS file: /cvs/drupal/drupal/themes/seven/template.php,v
retrieving revision 1.16
diff -u -r1.16 template.php
--- themes/seven/template.php	21 Apr 2010 06:55:23 -0000	1.16
+++ themes/seven/template.php	24 Apr 2010 10:08:35 -0000
@@ -2,16 +2,6 @@
 // $Id: template.php,v 1.16 2010/04/21 06:55:23 webchick Exp $
 
 /**
- * Override or insert variables into the html template.
- */
-function seven_preprocess_html(&$vars) {
-  // Add conditional CSS for IE8 and below.
-  drupal_add_css(path_to_theme() . '/ie.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lte IE 8', '!IE' => FALSE), 'preprocess' => FALSE));
-  // Add conditional CSS for IE6.
-  drupal_add_css(path_to_theme() . '/ie6.css', array('weight' => CSS_THEME, 'browsers' => array('IE' => 'lt IE 7', '!IE' => FALSE), 'preprocess' => FALSE));
-}
-
-/**
  * Override or insert variables into the page template.
  */
 function seven_preprocess_page(&$vars) {
Index: themes/seven/seven.info
===================================================================
RCS file: /cvs/drupal/drupal/themes/seven/seven.info,v
retrieving revision 1.5
diff -u -r1.5 seven.info
--- themes/seven/seven.info	14 Jan 2010 06:47:54 -0000	1.5
+++ themes/seven/seven.info	24 Apr 2010 10:08:35 -0000
@@ -7,6 +7,8 @@
 engine = phptemplate
 stylesheets[screen][] = reset.css
 stylesheets[screen][] = style.css
+stylesheets-conditional[lte IE 8][all][] = ie.css
+stylesheets-conditional[lt IE 7][all][] = ie6.css
 settings[shortcut_module_link] = 1
 regions[content] = Content
 regions[help] = Help
Index: themes/tests/test_theme/ie.css
===================================================================
RCS file: themes/tests/test_theme/ie.css
diff -N themes/tests/test_theme/ie.css
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ themes/tests/test_theme/ie.css	1 Jan 1970 00:00:00 -0000
@@ -0,0 +1,12 @@
+/* $Id$ */
+
+/**
+ * @file
+ * Test theme
+ * 
+ * Conditional stylesheet for IE browsers
+ */
+
+body {
+  zoom: 1;
+}