… @Library('libname@${BRANCH_NAME}') [JENKINS-69731]

To simplify co-existence of feature-branched pipeline scripts with
feature-branched Jenkins Shared Libraries, allow literal use of
    @Library('libname@${BRANCH_NAME}') _
lines to load a variant of a trusted (global) library with one case
of arbitrary branch naming.

This should be permitted by allowBRANCH_NAME checkbox (independent
of generic allowVersionOverride setting) in the first place.

If enabled, the value of BRANCH_NAME environment variable set by
the current build's Run object would be queried, and if resolvable -
verified with retriever.validateVersion() to match the backend
(Legacy SCM, Modern SCM, and other retrievers like HTTP/ZIP from
workflow-cps-global-lib-http-plugin).

…aultedVersion() for JENKINS-69731 related behaviors

…ns with BRANCH_NAME [JENKINS-69731]

… of an absent libname@bogusbranch

…RANCH and CHANGE_TARGET be considered as fallbacks [JENKINS-69731]

…Ms() and handle if it is GitSCM with branches, before looking at envvars [JENKINS-69731]

…; and then it is safer to check getSCMs() not for WorkflowRun, but for the FlowDefinition from WorkflowJob [JENKINS-69731]

…ersionStaticStrings() and limit influence of caller-defined BRANCH_NAME [JENKINS-69731]

…NKINS-69731]

…efaultVersion_BRANCH_NAME_notAllowed() cases [JENKINS-69731]

…me jobs twice [JENKINS-69731]

…S-69731]

…NS-69731]

…NKINS-69731]

…anch() - Need help setting up MBP+SingleSCMSource [JENKINS-69731]

…of trace info about decision making [JENKINS-69731]

…INS-69731]

…S-69731]

…[JENKINS-69731]

…ME() from checkDefaultVersion_inline_staticStrings() [JENKINS-69731]

…H_NAME() [JENKINS-69731]

…g [JENKINS-69731]

…t that many @Library lines do not confuse list of SCMs for BRANCH_NAME resolution [JENKINS-69731]

…AME() [JENKINS-69731]

…@Library('libname@${env.VARNAME}') support [JENKINS-69731]

…ersionEnvvar() [JENKINS-69731]

… "Tokens spelled in @Library annotation are not Groovy variables!" [JENKINS-69731]

...however for simplicity of "naive use" without knowledge of
the feature added with JENKINS-69731, the markup used for these
semi-variable version specifications is intentionally similar
to what "real" Groovy coders would use in their pipeline scripts.

…AME_doubleQuotes() [JENKINS-69731]

…731]

…nvvar() useful for at least one realistic use-case [JENKINS-69731]

…iated with FlowDefinition of a WorkflowJob, ask in the WorkflowJob itself for completeness [JENKINS-69731]

…nEnvvar() attempts for better test coverage [JENKINS-69731]

…has a BranchJobProperty, then envvar and then associated SCMs [JENKINS-69731]

…mbp.save() [JENKINS-69731]

…(): let devs easily tinker on currently failing part of test setup [JENKINS-69731]

This keeps build requirements and imports in the loop, so compilers and
IDEs do not complain or optimize away "unused" lines.

…of defaultedVersion() [JENKINS-69731]

…ic and camel-cased traceDefaultedVersion [JENKINS-69731]

…nch_*() cases [JENKINS-69731]

…(): add some debug traces [JENKINS-69731]

…(): add FreeStyle test line for ideas about building on an agent [JENKINS-69731]

…(): add envvar injection tests with EnvironmentContributor [JENKINS-69731]

…(): update comments [JENKINS-69731]

…(): drop attempts with envinject [JENKINS-69731]

…(): add back ecOrig to ecList [JENKINS-69731]

…(): WorkflowRun only accepts injected envvars if global config does not override them [JENKINS-69731]

…(): un-block test with injected envvars [JENKINS-69731]

…(): tag debug printouts with build number [JENKINS-69731]

…(): play with "built-in" node envvars [JENKINS-69731]

…wVersionEnvvar_builtIn() [JENKINS-69731]

…AME_after_staticStrings() for some TDD [JENKINS-69731]

…s(), it does not give the answers we are looking for

…b handling

…rride field

…er*() helpers

… helpers [JENKINS-69731]

…iesAreNotReusedByDifferentScms() is skipped on Windows

…NCH_NAME_lightweight() [JENKINS-69731]

… empty array [JENKINS-69731]

…f CpsScmFlowDefinition [JENKINS-69731]

…separate extractDefaultedVersionGitSCM() hack in a scalable manner [JENKINS-69731]

…MFS() [JENKINS-69731]

…ndant null-checks (spotbugs) [JENKINS-69731]

…r to get runVersion from SCMHead (needs practical confirmation) [JENKINS-69731]

…-BRANCH_NAME

…-BRANCH_NAME

…tion" tests

…o work around some GitSampleRepoRule.notifyCommit() issue

…-BRANCH_NAME

…-BRANCH_NAME

…-BRANCH_NAME