Index: src/wp-admin/includes/misc.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/includes/misc.php b/src/wp-admin/includes/misc.php
--- a/src/wp-admin/includes/misc.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/includes/misc.php	(date 1650029109007)
@@ -1410,7 +1410,7 @@
  * @param string $value     The proposed new site admin email address.
  */
 function update_option_new_admin_email( $old_value, $value ) {
-	if ( get_option( 'admin_email' ) === $value || ! is_email( $value ) ) {
+	if ( 0 === strcasecmp( get_option( 'admin_email' ), $value ) || ! is_email( $value ) ) {
 		return;
 	}
 
Index: src/wp-admin/includes/class-wp-screen.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/includes/class-wp-screen.php b/src/wp-admin/includes/class-wp-screen.php
--- a/src/wp-admin/includes/class-wp-screen.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/includes/class-wp-screen.php	(date 1650029108999)
@@ -1126,7 +1126,7 @@
 				update_user_meta( get_current_user_id(), 'show_welcome_panel', $welcome_checked );
 			} else {
 				$welcome_checked = (int) get_user_meta( get_current_user_id(), 'show_welcome_panel', true );
-				if ( 2 === $welcome_checked && wp_get_current_user()->user_email !== get_option( 'admin_email' ) ) {
+				if ( 2 === $welcome_checked && 0 !== strcasecmp( wp_get_current_user()->user_email, get_option( 'admin_email' ) ) ) {
 					$welcome_checked = false;
 				}
 			}
Index: src/wp-includes/ms-functions.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-includes/ms-functions.php b/src/wp-includes/ms-functions.php
--- a/src/wp-includes/ms-functions.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-includes/ms-functions.php	(date 1650029263528)
@@ -2802,7 +2802,7 @@
  * @param string $value     The proposed new network admin email address.
  */
 function update_network_option_new_admin_email( $old_value, $value ) {
-	if ( get_site_option( 'admin_email' ) === $value || ! is_email( $value ) ) {
+	if ( 0 === strcasecmp( get_site_option( 'admin_email' ), $value ) || ! is_email( $value ) ) {
 		return;
 	}
 
Index: src/wp-admin/includes/class-wp-automatic-updater.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/includes/class-wp-automatic-updater.php b/src/wp-admin/includes/class-wp-automatic-updater.php
--- a/src/wp-admin/includes/class-wp-automatic-updater.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/includes/class-wp-automatic-updater.php	(date 1650029108979)
@@ -258,7 +258,7 @@
 
 		// Don't notify if we've already notified the same email address of the same version.
 		if ( $notified
-			&& get_site_option( 'admin_email' ) === $notified['email']
+			&& 0 === strcasecmp( get_site_option( 'admin_email' ), $notified['email'] )
 			&& $notified['version'] === $item->current
 		) {
 			return false;
@@ -636,7 +636,7 @@
 		// Don't notify if we've already notified the same email address of the same version of the same notification type.
 		if ( $notified
 			&& 'fail' === $notified['type']
-			&& get_site_option( 'admin_email' ) === $notified['email']
+			&& 0 === strcasecmp( get_site_option( 'admin_email' ), $notified['email'] )
 			&& $notified['version'] === $core_update->current
 		) {
 			$send = false;
Index: src/wp-admin/user-edit.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/user-edit.php b/src/wp-admin/user-edit.php
--- a/src/wp-admin/user-edit.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/user-edit.php	(date 1650029263472)
@@ -519,7 +519,7 @@
 							<?php endif; ?>
 
 							<?php $new_email = get_user_meta( $current_user->ID, '_new_email', true ); ?>
-							<?php if ( $new_email && $new_email['newemail'] !== $current_user->user_email && $profile_user->ID === $current_user->ID ) : ?>
+							<?php if ( $new_email && 0 !== strcasecmp( $new_email['newemail'], $current_user->user_email ) && $profile_user->ID === $current_user->ID ) : ?>
 							<div class="updated inline">
 								<p>
 									<?php
Index: src/wp-admin/options-general.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/options-general.php b/src/wp-admin/options-general.php
--- a/src/wp-admin/options-general.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/options-general.php	(date 1650029109031)
@@ -114,7 +114,7 @@
 <p class="description" id="new-admin-email-description"><?php _e( 'This address is used for admin purposes. If you change this, an email will be sent to your new address to confirm it. <strong>The new address will not become active until confirmed.</strong>' ); ?></p>
 <?php
 $new_admin_email = get_option( 'new_admin_email' );
-if ( $new_admin_email && get_option( 'admin_email' ) !== $new_admin_email ) :
+if ( $new_admin_email && 0 !== strcasecmp( get_option( 'admin_email' ), $new_admin_email ) ) :
 	?>
 	<div class="updated inline">
 	<p>
Index: src/wp-admin/_index.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/_index.php b/src/wp-admin/_index.php
--- a/src/wp-admin/_index.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/_index.php	(date 1650029109023)
@@ -175,7 +175,7 @@
 
 	$option = (int) get_user_meta( get_current_user_id(), 'show_welcome_panel', true );
 	// 0 = hide, 1 = toggled to show or single site creator, 2 = multisite site owner.
-	$hide = ( 0 === $option || ( 2 === $option && wp_get_current_user()->user_email !== get_option( 'admin_email' ) ) );
+	$hide = ( 0 === $option || ( 2 === $option && 0 !== strcasecmp( wp_get_current_user()->user_email, get_option( 'admin_email' ) ) ) );
 	if ( $hide ) {
 		$classes .= ' hidden';
 	}
Index: src/wp-includes/user.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-includes/user.php b/src/wp-includes/user.php
--- a/src/wp-includes/user.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-includes/user.php	(date 1650029264904)
@@ -2332,7 +2332,7 @@
 	}
 
 	if ( $update ) {
-		if ( $user_email !== $old_user_data->user_email || $user_pass !== $old_user_data->user_pass ) {
+		if ( 0 !== strcasecmp( $user_email, $old_user_data->user_email ) || $user_pass !== $old_user_data->user_pass ) {
 			$data['user_activation_key'] = '';
 		}
 		$wpdb->update( $wpdb->users, $data, array( 'ID' => $user_id ) );
@@ -2531,7 +2531,7 @@
 		$send_password_change_email = apply_filters( 'send_password_change_email', true, $user, $userdata );
 	}
 
-	if ( isset( $userdata['user_email'] ) && $user['user_email'] !== $userdata['user_email'] ) {
+	if ( isset( $userdata['user_email'] ) && 0 !== strcasecmp( $user['user_email'], $userdata['user_email'] ) ) {
 		/**
 		 * Filters whether to send the email change email.
 		 *
Index: src/wp-admin/network/settings.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/wp-admin/network/settings.php b/src/wp-admin/network/settings.php
--- a/src/wp-admin/network/settings.php	(revision 189a047cb8a5a99c752afc742eb71f2653fa65c5)
+++ b/src/wp-admin/network/settings.php	(date 1650029110592)
@@ -166,7 +166,7 @@
 					</p>
 					<?php
 					$new_admin_email = get_site_option( 'new_admin_email' );
-					if ( $new_admin_email && get_site_option( 'admin_email' ) !== $new_admin_email ) :
+					if ( $new_admin_email && 0 !== strcasecmp( get_site_option( 'admin_email' ), $new_admin_email ) ) :
 						?>
 						<div class="updated inline">
 						<p>