Catch the potential DB errors when "#__postinstall_messages" is missing

[jms2win]

Based on comment from bakual in PR 2822, I have move this PR from master to staging and also included the enhancement frm mbabker
#2821

[Bakual]

Changed title of the PR to the title of the original PR.
Also adding here the description of original PR:

When we proceed with a manual upgrade from Joomla 2.5.17 to J3.2.1 by an unzip of J3.2.1 full package over a current J2.5.17 installation, the #__postinstall_messages is not present and cause the impossibility to login due to the "cPanel" that always abort on DB Error.

The purpose of this fix is to intercept such kind of errors and let the cPanel displayed without any "Post Install Messages".

Comment history can be seen in original PR.

[jms2win]

Sorry but I don't understand what you want that I do and where.

The title of which PR do you want that I change ?
The exact number please.

I think that I have clearly identified in the new PR that I have created at your request and it makes reference to this one (PR).
So all the information can be retrieved and also from the Bugtracker as this one also make reference to the new PR

If you want to add comments in the new PR to make them more clear, this is possible.

Do you want that I add a comment in the Bugtracker to mentioned the new PR, this is also possible but you can do it also.

Sorry but I am not fluent with PR.

[Bakual]

All well 👍

[infograf768]

This has to be updated to present state of staging

[sovainfo]

Although I agree with this being done for the wrong reason (bad migration strategy as mentioned by @brianteeman ) I would like this to be extended to the complete RAD layer, not only the database problem.

Expect the Control Panel to be fault tolerant and not to fail just because one of its components fail.

[roland-d]

@jms2win Could you please update to the latest staging? Thanks.

[jms2win]

@roland-d can you be more precise of what you expect from me.
I don't understand what I have to do.
I see that that travis did something and that somebody seems want that I comit something but I don't know where and how to do that.
If you are admin, can you acknowledge this very old pull request

[zero-24]

@jms2win if you don't know how you can update to staging or fix merge conflicts. You can simple close here and open a new PR against staging. The problem is that the file you what to patch is changed since you open the PR. So we can't merge it. 😄

[jms2win]

@zero-24
OK - I will close as nobody had a look on it on more than 1 year and that I don't know how to manage the merge.
So I let you apply the change.

[zero-24]

done here: #6252 Thanks @jms2win

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