Fixed GH-18348: fputcsv incorrectly escapes when quote char is both enclosure and escape char

[SakiTakamachi]

Fixes #18348

[vavra]

@SakiTakamachi was this commit applied to branch 8.4.7 ?
For
$row = ['J"a"n', 'He said "Hello"', 'Line1\Line2'];
still getting on this version output
"J""a"n","He said ""Hello""",Line1\Line2

no doubled " before n in first col

[SakiTakamachi]

@vavra

No, I didn’t merge it.
Since this behavior is described in the documentation, I didn’t consider it a bug.

#18348 (comment)