* lisp/erc/erc.el (erc--initialize-markers): New helper to ensure
prompt and its associated markers are set up correctly.
(erc-open): When determining whether a session is a logical
continuation, leverage the work already performed by the
`erc-networks' library to that effect. Its verdicts are based on
network context and thus reliable even when a user dials anew from an
entry-point, which is not a simple reconnection because the user
expects a clean slate for everything except an existing buffer's
messages, meaning `erc--server-reconnecting' will be nil and
local-module state variables need resetting. Also remove the check
for `erc-reuse-buffers' and instead trust that `erc-get-buffer-create'
always does the right thing. Replace all code involving marker and
prompt setup by deferring to a new helper, `erc--initialize markers'.
* test/lisp/erc/erc-scenarios-base-local-module-modes.el: New file.
* test/lisp/erc/erc-scenarios-base-local-modules.el
(erc-scenarios-base-local-modules--mode-persistence): Move test to
separate file to help with parallel "-j" runs.
* test/lisp/erc/erc-tests.el (erc-tests--send-prep): Replace
redundant prompt-setup code.
(erc--initialize-markers): New test. (Bug#60936.)
* test/lisp/erc/erc-scenarios-base-compat-rename-bouncer.el: Fix file
name in prop line and footer.
* test/lisp/erc/erc-scenarios-base-local-modules.el: Fix file name in
prop line and footer.
* test/lisp/erc/erc-scenarios-base-netid-samenet.el: Fix file name in
prop line and footer.
* test/lisp/erc/erc-scenarios-base-upstream-recon-soju.el: Fix file
name in prop line and footer.
* test/lisp/erc/erc-scenarios-base-upstream-recon-znc.el: Fix file
name in prop line and footer.
* lisp/erc/erc.el (erc--target-priors): New internal variable to do
for target buffers what `erc--server-reconnecting' does for server
buffers.
(erc-open): Source the state of a local module's mode variable from
its actual buffer rather than its server buffer. Additionally, make
all local variables from a prior session available to
module-activation functions and `erc-mode' hooks, even when
`erc-reuse-buffers' is nil. This bug arrived with the introduction of
"local-modules" (bug#57955).
* test/lisp/erc/erc-scenarios-base-local-modules.el
(erc-scenarios-base-local-modules--toggle-helpers): Remove useless
`with-current-buffer'.
(erc-scenarios-base-local-modules--local-var, erc--phony-sblm--enable,
erc--phony-sblm--disable, erc--phony-sblm--mode): Add fake local
module and data var for test scenario.
(erc-scenarios-base-local-modules--var-persistence) Add slightly hacky
test case with promise to improve later when splitting the file.
* test/lisp/erc/erc-scenarios-base-local-modules.el: New file.
* test/lisp/erc/resources/base/local-modules/first.eld: New file.
* test/lisp/erc/resources/base/local-modules/fourth.eld: New file
* test/lisp/erc/resources/base/local-modules/second.eld: New file.
* test/lisp/erc/resources/base/local-modules/third.eld: New file.
(Bug#57955.)
