parameter to DiscoveryTrait::doGetDefinition() is incorrectly documented as optional

Removed the optional word but still doubt about "Defaults to False" because there is no default value set for this variable.

Hi!
Acording to @joachim on #3, remove 'Defaults to False' text.

+++ b/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php
@@ -30,8 +30,7 @@ public function getDefinition($plugin_id, $exception_on_invalid = TRUE) {
+   *   If TRUE, an invalid plugin ID will throw an exception.

This seems slightly incomplete, and leaves me wondering about what happens if it is FALSE.

What if we said something like:

TRUE to throw an exception if the plugin ID is invalid; FALSE to return NULL in this case.

I guess that somewhat overlaps with the @return, but at least it doesn't leave you wondering what happens if it's FALSE. Thoughts?

The grammar in that suggestion in #6 is a bit questionable -- the two clauses don't have parallel verb tenses: "will cause" vs. "returning". It's also kind of passive voice.

Here are some alternatives, which all at least have parallel grammatical constructions:
- TRUE to throw an exception if the plugin ID is invalid; FALSE to return NULL in this case.
- If TRUE, an invalid plugin ID will cause an exception to be thrown; if FALSE, NULL will be returned.
- Determines what happens if the plugin ID is invalid. TRUE will cause an exception to be thrown; FALSE will cause NULL to be returned.
- Determines what happens if the plugin ID is invalid. If TRUE, an exception will be thrown; if FALSE, NULL will be returned.

Looking at these, I think "cause" is kind of awkward, so let's avoid those alternatives? Other than that, pick one of the above, or come up with another alternative that also has parallel verb grammar. OK?

fix #4 to #7 :)

Sorry. attach valid patch and interdiff

Sorry, bad files Ew!

Applying Patch.

Thanks!!

Sorry for wrong patch applied.

:) #4 with #7

#15 is write patch and # 13 is wrong patch.

Thanks!!

#16 is the wrong patch, because it has a line that is too long.
#15 looks fine to me.

To avoid the wrong patch being tested/committed, I am uploading the #15 patch again and hiding all the other patches.

Thanks!

Committed 68cc3af and pushed to 8.1.x and 8.2.x. Thanks!