Extra semicolon & wrong spacing between dot and concatenated parts in common.inc

Both parts of the semicolon are properly removed. Nice.

+++ b/core/includes/common.inc
@@ -4221,7 +4221,7 @@ function drupal_render_cache_generate_placeholder($callback, array $context, $to
-  return '<drupal:render-cache-placeholder callback="' . $callback .  '" context="' . $context_attribute . '" token="'. $token . '" />';;
+  return '<drupal:render-cache-placeholder callback="' . $callback .␣␣'" context="' . $context_attribute . '" token="'. $token . '" />';
 }

There are a couple of space that I've marked with "␣" right after the second callback (only one is necessary), are we're also missing a space in between the first token and its following ".".

Patch whitespaces look good now, back to RTBC. Thanks @malionek for following up after the Boston code sprint!

Nice work getting a handle on the process for core contributions, @malionek --the semicolon is just a start!

That said, out of curiosity I grepped for other occurrences of double semicolons. Seems there are more of the same type of fix needing attention. Care to take on others?

If so, in Terminal on your Mac, navigate to your d8 docroot again and at the $ prompt enter the following (including the period):
grep -r ';;' .
You'll get a list of a few files that match that pattern.

You'll want to create a new issue for these other fixes, since they are unrelated to this one (I bet I'm breaking that protocol by bringing these other semicolons up here, fwiw).

Ignore the binary files (e.g. Binary file ./core/modules/views_ui/images/loading.gif ...) and ones that have any of the following in the path:

• .git (e.g. ./.git/hooks/update.sample: ;;)
• vendor (e.g. ./core/assets/vendor/modernizr/modernizr.js:});;)

Feel free to ping me on #drupal-ladder if you'd like more info or get stuck. Naturally, core mentoring hours (see drupalmentoring.org) are also a great way to get insights/help on core contribution.

Committed f17c8b3 and pushed to 8.x. Thanks!