Your mental model of what «.+?» does is severely flawed. For starters, it doesn't permit patterns to have multiple subpatterns that can match substrings of different lengths.

«.+?» does not mean "the shortest possible match within the string that starts with a comma".

«.+» means "one or more non-LF characters, trying in order of decreasing length", and
«.+?» means "one or more non-LF characters, trying in order of increasing length".

Note that lack of mention of comma. «.+?» doesn't do any checks related to commas. The comma is matched independently.

In reply to Re^3: Non-greedy substitution by ikegami
in thread Non-greedy substitution by Bod

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