[JENKINS-19413] Use CredentialsDescriptor.findContextInPath rather than directly StaplerRequest2.findAncestorObject

[jglick]

Fixes jenkinsci/ec2-fleet-plugin#491 and similarly enables jenkinsci/jenkins#11055.

Using utility from #62 (comment) rather than copying StaplerReferer from other plugins, where it is limited to Item (here we actually need User at least). See also #373 (comment).

[jtnord]

The existing code had a check that we are in a Stapler request. if that was needed this will now throw a NullPointerException, did you check that calls to this are only web methods?

[jglick]

Can double check but the other overload of this method passed in StaplerRequest2 already without checking. (It would make no sense outside of a request context.)

[jglick]

CredentialsSelectHelper methods touched here are used from

credentials-plugin/src/main/resources/lib/credentials/select.jelly

Line 67 in f8963c3

<j:set var="context" value="${selectHelper.resolveContext(attrs.context ?: it)}"/>

credentials-plugin/src/main/resources/lib/credentials/select.jelly

Lines 115 to 117 in f8963c3

	<j:set var="storeItems" value="${selectHelper.getStoreItems(context, includeUser)}"/>
	<j:choose>
	<j:when test="${selectHelper.hasCreatePermission(context, includeUser) and storeItems != null and !storeItems.isEmpty()}">

Whereas

credentials-plugin/src/main/java/com/cloudbees/plugins/credentials/CredentialsDescriptor.java

Line 328 in f8963c3

public static <T extends ModelObject> T findContextInPath(@NonNull StaplerRequest2 request, @NonNull Class<T> type) {

is used from

credentials-plugin/src/main/java/com/cloudbees/plugins/credentials/ContextInPath.java

Line 44 in f8963c3

return CredentialsDescriptor.findContextInPath(request, type);

[jtnord]

The existing code had a check that we where in a Stapler request. if that was needed this will now throw a NullPointerException, did you check that calls to this are only web methods, or that null is never passed for any non web methods?

[jglick]

#651 (comment) again