Bug #20474: Heredoc common leading whitespace calculation question

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[kddnewton (Kevin Newton)]

I think I understand that <<~ will strip common leading whitespace from all lines. However, I am confused by the following example:

eval("<<~H\n     \nh\n     \nH\n")

In this example, the heredoc has 3 lines: " \n", "h\n", and " \n". The common leading whitespace is definitely 0, because of the 2nd line.

However, the string is equal to "\nh\n\n". In fact, no matter how many spaces you put before the h, it will always be equal to "\nh\n\n".

I'm not sure if this is a bug, or even what is happening here. Could someone explain?

[nobu (Nobuyoshi Nakada)]

It looks like a bug.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|5bb656e4f063e717262efe2dc303ed914eb1dd6c.

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[Bug #20474] Keep spaces in leading blank line

[kddnewton (Kevin Newton)]

Thank you!

[Dan0042 (Daniel DeLorme)]

However, the string is equal to "\nh\n\n".

I would have expected it to be

"     \nh\n     \n"

but ignoring all whitespace from blank lines seems like a convenient feature to me.

In fact, no matter how many spaces you put before the h, it will always be equal to "\nh\n\n".

I'm pretty sure that's normal; many/most editors will strip the indentation of blank lines, so we want common leading whitespace to be computed only for lines that have some non-whitespace character.