ELSE expressions terminate early when encountering an END token

[SharpDerek]

CASE statements with an ELSE returning a value with the "tablename.columnname" format fail due to encountering an END token and parsing it as if it were a column instead. This fixes the issue by checking to see if the current token is an END and breaks before column processing.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.30%. Comparing base (f440917) to head (70b388b).

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #654   +/-   ##
=========================================
  Coverage     96.30%   96.30%           
- Complexity     2254     2255    +1     
=========================================
  Files            90       90           
  Lines          4982     4982           
=========================================
  Hits           4798     4798           
  Misses          184      184           

Flag	Coverage Δ
unit-8.2-ubuntu-latest	96.30% <100.00%> (ø)
unit-8.3-ubuntu-latest	96.30% <100.00%> (ø)
unit-8.4-ubuntu-latest	96.30% <100.00%> (ø)
unit-8.5-ubuntu-latest	96.30% <100.00%> (ø)

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[williamdes]

Thank you for this fix. If possible please reset your branch to 5.11.x and cherry pick your work and force push.
It will allow us to have the fix on 5.11.x
Else just let me know and I will do it manually

[williamdes]

Also, please add test cases

[SharpDerek]

Also, please add test cases

Here's the most succinct test case I can provide:

SELECT
    CASE
        WHEN table_a.column_a = 'FOO'
        THEN table_b.column_a
        ELSE table_b.column_b
END AS foo

Output before change:

SELECT
    CASE foo
    ELSE table_b.column_b AS `END`
END

Output after change:

SELECT
    CASE WHEN table_a.column_a = 'FOO'
    THEN table_b.column_a
    ELSE table_b.column_b
END AS `foo`

[SharpDerek]

If this gets merged into 5.11.x, would it be put into 6.0.0 as well? That is the version that we are currently running and can't really downpatch.