Change module_exist to module_exists

Ditto ditto ditto.

+1 cause webchick told me to

Those two reasons webchick mentioned. Setting to critical because I just can't stand another release with this.

nice use of legacy module!

+1. Booyah.

+100, because this is a beautiful thing. webchick didn't have to tell me to say it. ;)

this is a nice touch in legacy.module:

+ * This function is identical to module_exists, but is provided for backwards
+ * compatibility.
...
+function module_exist($module) {
+  $list = module_list();
+  return array_key_exists($module, $list);
+}

anyway, definitely a good move, definitely RTBC. ;)

hell yes +1

keep making the same ol mistake of exists rather than exist

Probably not really an appropriate use of critical, as things work fine without it. But it's a persistent, long-term misspelling that makes checking modules counter-intuitive. Just because it's not critical doesn't mean that this typo in a key core function doesn't make baby Jesus cry.

+1, Also there are a lot of other php functions that use exists vs exist

see http://www.php.net/manual-lookup.php?pattern=exists&lang=en to see more like file_exists(), class_exists(), ...

Good catch. Committed to HEAD.

I don't really like the legacy.module part though... modules need to be updated for 4.8 anyway, and it's a search-and-replace change that is easily documented.