drupal 7.50 发布了，Drupal 7 系列为维护版本，该版本新增一些小功能，以及修复一些问题，增强一些旧有功能。值得注意的是，对之前版本的兼容性不是很好。
以下是两个比较重要的改进：
主要改进记录：
#611294: Added a new "administer fields" permission for trusted users, which is required in addition to other permissions to use the field UI (change record).
#2514136: Added clickjacking protection to Drupal core by setting the X-Frame-Options header to SAMEORIGIN by default (change record).
#2488180: Added support for full UTF-8 (emojis, Asian symbols, mathematical symbols) on MySQL and other database drivers when the site and database are configured to allow it (change record).
#1081266: Improved performance by avoiding a re-scan of directories when a file is missing; instead, trigger a PHP warning (minor API change; see the change record).
#2747679 and #2760609: Made it possible to use any PHP callable in Ajax form callbacks, form API form-building functions, and form API wrapper callbacks (API addition; see the change record).
#889772: Fixed that following a password reset link while logged in leaves users unable to change their password (minor user interface change; see the change record).
#2620104 and #2656548: Implemented various fixes for automated test failures on PHP 5.4+ and PHP 7. Drupal core automated tests now pass in these environments.
#2656548: Improved support for PHP 7 by fixing various problems.
#2215369: Fixed various bugs with PHP 5.5+ imagerotate(), including when incorrect color indices are passed in.
#2678822: Fixed a regression introduced in Drupal 7.43 that allowed files uploaded by anonymous users to be lost after form validation errors, and that also caused regressions with certain contributed modules.
#2502263: Fixed a regression introduced in Drupal 7.36 which caused the default value of hidden textarea fields to be ignored.
#2364343: Fixed robots.txt to allow search engines to access CSS, JavaScript and image files (change record).
#2470145: Changed wording on the Update Manager settings page to clarify that the option to check for disabled module updates also applies to uninstalled modules (administrative-facing translatable string change).
#2418209: Changed the help text when editing menu links and configuring URL redirect actions so that it does not reference "Drupal" or the drupal.org website (administrative-facing translatable string change).
#2371861: Fixed the locale safety check that is used to ensure that translations are safe to allow for tokens in the href/src attributes of translated strings.
#1645156: Fixed that URL generation only works on port 80 when using domain based language negotation.
#1116326: Made method="get" forms work inside the administrative overlay. The fix adds a new hidden field to these forms when they appear inside the overlay (minor data structure change).
#2578173: Increased maxlength of menu link title input fields in the node form and menu link form from 128 to 255 characters.
#2646280: Removed meaningless post-check=0 and pre-check=0 cache control headers from Drupal HTTP responses.
#1713662: Added a .editorconfig file to auto-configure editors that support it (change record).
#2551981: Added --directory option to run-tests.sh for easier test discovery of all tests within a project.
#2189345: Made run-tests.sh exit with a failure code when there are test fails or problems running the script.
#2491353: Fixed that cookies from previous tests are still present when a new test starts in DrupalWebTestCase.
#2634840: Improved performance of queries on the {authmap} database table.
#412808: Fixed handling of missing files and functions inside the registry.
#1458824: Fixed Ajax handling for tableselect form elements that use checkboxes.
#1327728: Fixed a bug which caused ip_address() to return nothing when the client IP address and proxy IP address are the same.
#2393461: Added a new option to format_xml_elements() to allow for already encoded values.
#2633334: Changed the {history} table's node ID field to be an unsigned integer, to match the same field in the {node} table and to prevent errors with very large node IDs.
#2674028: Added an explicit page callback to the "admin/people/create" menu item in the User module (minor data structure change). Previously this automatically inherited the page callback from the parent "admin/people" menu item, which broke contributed modules that override the "admin/people" page.
查看更多改进信息，直接查看发布说明。