Fix: remove extra call serializeout connection.py

[joshStillerman]

#2661 changed the expr to be evaluated enclosing it in a call to serializeout

When connecting to older mdsip servers - like:

TCL> show version

MDSplus version: 7.78.6
----------------------
  Release:  alpha_release-7-78-6
  Browse:   https://github.com/MDSplus/mdsplus/tree/alpha_release-7-78-6
  Download: https://github.com/MDSplus/mdsplus/archive/alpha_release-7-78-6.tar.gz
  Build date: Wed Jun 26 18:51:44 UTC 2019

TCL>

This causes calls like TreeOpen('tree', shot) to generate an infinte recursion error,

This PR removes line 208 from connection.py

GABRIELE: Does this break #2660/#2661 ??

[mwinkel-dev]

A related APD change is in the earlier PR #2620.

[joshStillerman]

Gabriele -
It could be that:

• The code should check if it is an APD instead of just 'not serializing' as I did in this PR
• Whatever the fix turns out to be, it probably will be needed in all of the languages that you fixed

[joshStillerman]

Gabriele -
It could be that:

• The code should check if it is an APD instead of just 'not serializing' as I did in this PR
• Whatever the fix turns out to be, it probably will be needed in all of the languages that you fixed

[mwinkel-dev]

Hi @joshStillerman,

This fix was manually tested with MATLAB R2023b on Ubuntu 20 and it successfully read and plotted a signal (i.e., Issue #2660 did not reappear). The signal was retrieved without error regardless of whether connecting to server A or server B.

However, a cross-version error was found as is shown below.

Success

>> 
>> mdsconnect('<server A>');           % has MDSplus alpha_release_7.112.1
>> mdsopen('cmod',1090909009);
>> mdsclose();
>> mdsdisconnect();
>> 

Failure

>> 
>> mdsconnect('<server B>');           % has MDSplus alpha_release-7-78-6
>> mdsopen('cmod',1090909009);
>> mdsclose();

ans =

    'Java exception occurred: 
     MDSplus.MdsException: %TDI-E-RECURSIVE, Overly recursive function, calls itself maybe
     	at MDSplus.Connection.get(Native Method)
     	at MDSplus.Connection.get(Connection.java:117)'

>> mdsdisconnect();
>>

[joshStillerman]

Do not merge - needs discussion

[mwinkel-dev]

See comments in PR #2720.

[mwinkel-dev]

Initial bug report was for thin-client with the Python API's connection.openTree(<tree>, <shot>) method. And the alpha-7-78-6 was probably running on an Ubuntu 18 server.

[mwinkel-dev]

Closing this PR as per @joshStillerman. Refer to PR #2720 for the full history of the APD related problems.