Support combined "any" / "all" filters with mail clients that do (Betterbird 91.8)

[RealRaven2000]

The new version of Betterbird will support filters that allow mixing nested search conditions in which the operators "any" (OR) and "all" (AND) are supported, such as this:

[RealRaven2000]

this means that certain things need to be reviewed:

1. The "Sort search terms" function needs to be redesigned - we cannot assume all search terms are in the same group because it will destroy the logic of the filter if they are re-ordered. sorting could be done within a simple subgroup (like 2 groups shown in the example above) but even then care must be taken because the parentheses (beginsGrouping / endsGrouping) are stored in the first / last term of each group and not separately. This means if the first / last item are reordered then beginsGrouping / endsGrouping have to be transferred to the first / last item in the grouped list of conditions. At the beginning I suggest we disable sorting for any more complicated filter expression
2. make sure we do not lose information when storing filters. I assume this should be alright as no new attributes have been added.
3. The trouble-shooter will currently flag filters that have mixed (any + all) operators. This test needs to be disabled for mail clients which have the option of using mixed operators.

• How to determine securely whether the mixed operator is supported?
• in the patch written by Joerg K, 2 dummy attribute / functions have been removed. For now, we can use this as sign for the new functionality being supported. The hope is that if Thunderbird (ever) merges the changes they should adopt this part of the patch as well. I pan to use the absence of the dummy function nsMsgFilter.addTerm() to know that mixed / complex search terms are supported.

Betterbird github issue: Betterbird/thunderbird-patches#35

Here is the relevant patch with initial number of significant changes.

[ThiloteE]

Just for the record: There have been further related changes to Betterbird in:

• Betterbird #60
• Betterbird #62

Quickfilters most significantly will be affected by Betterbird/thunderbird-patches#62 (comment)

[ThiloteE]

Has this been solved or is it still on the to do list?

[RealRaven2000]

Has this been solved or is it still on the to do list?

I support creating filters and custom filter templates, also backup and restore. Merging is still an open question.