Ports a ZAS CSRFZ improvement. (#14487)

code/ZAS/Turf.dm

@@ -77,6 +77,11 @@
 	var/check_dirs
 	GET_ZONE_NEIGHBOURS(src, check_dirs)
 	. = check_dirs
+
+	//src is only connected to the zone by a single direction, this is a safe removal.
+	if (!(. & (. - 1)))
+		return TRUE
+
 	for(var/dir in csrfz_check)
 		//for each pair of "adjacent" cardinals (e.g. NORTH and WEST, but not NORTH and SOUTH)
 		if((dir & check_dirs) == dir)

html/changelogs/mattatlas-csrfz.yml

@@ -0,0 +1,41 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes:
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#   balance
+#   admin
+#   backend
+#   security
+#   refactor
+#################################
+
+# Your name.
+author: Kapu1178, Lohikar, MattAtlas
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - backend: "Ported a ZAS performance improvement."