bug#31742: 26.1.50; excorporate.elc byte-compiled in Emacs 25.x fails in Emacs 26.1

[Thomas Fitzsimmons]

Hi,

An Excorporate user reported an issue when running on Emacs 26.1 that
didn't happen in Emacs 25.3.

The error message, when trying to retrieve calendar items on a given day
is:

soap-find-operation: Wrong type argument: soap-binding, 
("http://schemas.microsoft.com/exchange/services/2006/messages"; . 
"ExchangeServiceBinding")

The simplest workaround is:

   M-x package-reinstall RET excorporate RET

I narrowed the cause down to what seems to be an incompatibility between
25.x bytecode and 26.1.  This issue only happens when excorporate.elc
has been byte compiled in Emacs 25.x (the .x doesn't seem to matter; I
replicated it on Emacs 25.1) and is then run in Emacs 26.1.  It doesn't
happen with a fresh package install on 25.x or 26.1.

When in the failure state, if I re-eval this function:

(defun exco--bind-wsdl (wsdl service-url port-name target-namespace
                             binding-name)
  "Create a WSDL binding.
Create a binding port for WSDL from SERVICE-URL, PORT-NAME,
TARGET-NAMESPACE and BINDING-NAME."
  (let* ((namespace (soap-wsdl-find-namespace target-namespace wsdl))
         (port (make-soap-port
                :name port-name
                :binding (cons target-namespace binding-name)
                :service-url service-url)))
    (soap-namespace-put port namespace)
    (push port (soap-wsdl-ports wsdl))
    (soap-resolve-references port wsdl)
    wsdl))

everything works.

In terms higher level functionality, it seems like the call to
soap-resolve-references has no effect.

I'm attaching the 25.1 and 26.1 bytecode for this function,
disassembled.  Maybe someone can identify what's wrong or suggest next
steps?

Thank you,
Thomas

exco--bind-wsdl-dump-25.1.txt
Description: Text document

exco--bind-wsdl-dump-26.1.txt
Description: Text document