Index: src/wp-includes/media.php
===================================================================
--- src/wp-includes/media.php	(revision 35953)
+++ src/wp-includes/media.php	(working copy)
@@ -1278,26 +1278,32 @@
 		return $image;
 	}
 
-	$base_url = trailingslashit( _wp_upload_dir_baseurl() );
-	$image_base_url = $base_url;
+	/**
+	 * To make sure that our ID and image src match, we loop through all the sizes
+	 * in our attachment metadata and bail early if our src file isn't included.
+	 *
+	 * Checks only for the presence of 'filename.ext' or 'year/month/filename.ext' (when upload sub-directories are used)
+	 * to accomodate for CDN enabling plugins that diredtly replace image sources in post_content.
+	 */
+	if ( strpos( $image_src, $image_meta['file'] ) === false ) {
+		$sub_sizes = wp_list_pluck( $image_meta['sizes'], 'file' );
 
-	$dirname = dirname( $image_meta['file'] );
-	if ( $dirname !== '.' ) {
-		$image_base_url .= trailingslashit( $dirname );
-	}
+		$dirname = dirname( $image_meta['file'] );
+		$dirname = $dirname === '.' ? '' : trailingslashit( $dirname );
 
-	$all_sizes = wp_list_pluck( $image_meta['sizes'], 'file' );
+		$matched = false;
 
-	foreach ( $all_sizes as $key => $file ) {
-		$all_sizes[ $key ] = $image_base_url . $file;
-	}
+		foreach( $sub_sizes as $size ) {
+			if ( strpos( $image_src, $dirname . $size ) !== false ) {
+				$matched = true;
+				break;
+			}
+		}
 
-	// Add the original image.
-	$all_sizes[] = $base_url . $image_meta['file'];
-
-	// Bail early if the image src doesn't match any of the known image sizes.
-	if ( ! in_array( $image_src, $all_sizes ) ) {
-		return $image;
+		// Bail early if the image src doesn't match any of the known image sizes.
+		if ( ! $matched ) {
+			return $image;
+		}
 	}
 
 	$width  = preg_match( '/ width="([0-9]+)"/',  $image, $match_width  ) ? (int) $match_width[1]  : 0;
Index: tests/phpunit/tests/media.php
===================================================================
--- tests/phpunit/tests/media.php	(revision 35953)
+++ tests/phpunit/tests/media.php	(working copy)
@@ -1133,4 +1133,42 @@
 		// Intermediate sized GIFs should not include the full size in the srcset.
 		$this->assertFalse( strpos( wp_calculate_image_srcset( $size_array, $large_src, $image_meta ), $full_src ) );
 	}
+
+	/**
+	 * @ticket 35045
+	 * @ticket 33641
+	 */
+	function test_wp_make_content_images_responsive_schemes() {
+		$image_meta = wp_get_attachment_metadata( self::$large_id );
+		$size_array = $this->_get_image_size_array_from_name( 'medium' );
+
+		$srcset = sprintf( 'srcset="%s"', wp_get_attachment_image_srcset( self::$large_id, $size_array, $image_meta ) );
+		$sizes  = sprintf( 'sizes="%s"', wp_get_attachment_image_sizes( self::$large_id, $size_array, $image_meta ) );
+
+		// Build HTML for the editor.
+		$img          = get_image_tag( self::$large_id, '', '', '', 'medium' );
+		$img_https    = str_replace( 'http://', 'https://', $img );
+		$img_relative = str_replace( 'http://', '//', $img );
+
+		// Manually add srcset and sizes to the markup from get_image_tag().
+		$respimg          = preg_replace( '|<img ([^>]+) />|', '<img $1 ' . $srcset . ' ' . $sizes . ' />', $img );
+		$respimg_https    = preg_replace( '|<img ([^>]+) />|', '<img $1 ' . $srcset . ' ' . $sizes . ' />', $img_https );
+		$respimg_relative = preg_replace( '|<img ([^>]+) />|', '<img $1 ' . $srcset . ' ' . $sizes . ' />', $img_relative );
+
+		$content = '
+			<p>Image, http: protocol. Should have srcset and sizes.</p>
+			%1$s
+
+			<p>Image, http: protocol. Should have srcset and sizes.</p>
+			%2$s
+
+			<p>Image, protocol-relative. Should have srcset and sizes.</p>
+			%3$s';
+
+		$unfiltered = sprintf( $content, $img, $img_https, $img_relative );
+		$expected   = sprintf( $content, $respimg, $respimg_https, $respimg_relative );
+		$actual     = wp_make_content_images_responsive( $unfiltered );
+
+		$this->assertSame( $expected, $actual );
+	}
 }