TYPO3 Core

How to replicate:
Create a content element table with following structure and leave all other settings with default values

1a | 1b | 1c
2a | 2b | 
3a | 3b | 3c

Add an empty space at the end of line 2. (Could easily happen, ie. if you remove the content from that cell, but leave the empty space)

Result:
Table is broken, because the empty space is handled as start of new table cell, but this cell is never closed, thus merging the whole line 3 into that cell.

Possible fix, add following TypoScript:

tt_content.table {
    dataProcessing {
        10 {
            fieldEnclosure.if.value = 0
            fieldEnclosure.if.equals.field = table_enclosure
            fieldEnclosure.if.negate = 1
        }
    }
}

Applies also for 8 LTS