Nulls in an unprotected field straddling a margin

When the tab key causes the cursor to skip to the left margin of the next line, and an unprotected field straddles the left margin, nulls that lie outside the left margin in the unprotected field are converted to spaces. However, when the tab key causes the cursor to skip to the next line, and an unprotected field straddles the right margin of the preceding line, nulls that lie outside the right margin in the unprotected field are not converted to spaces.