Re: BUG: CR marker ^M doesn't show up in '-' lines of diffs when the ending of the removed line is CR+LF

From: Johannes Sixt <j6t@kdbg.org>
Date: Nov 23, 2018, 21:47 UTC
Message-ID: <4dca3f64-4851-6d48-8266-dfe55f597739@kdbg.org>
In-Reply-To: <1f068f3a-d636-9b9c-f501-51d33412b964@googlemail.com>

Am 23.11.18 um 19:19 schrieb Frank Schäfer:

Show 5 quoted lines

> The CR marker ^M doesn't show up in '-' lines of diffs when the ending
> of the removed line is CR+LF.
> It shows up as expected in '-' lines when the ending of the removed line
> is CR only.
> It also always shows up as expected in '+' lines.

Is your repository configured to (1) highlight whitespace errors in diff output and (2) to leave CRLF alone in text files?

If so, then it is just a side-effect of this combination, an illusion, so to say: The CR in the CRLF combo is trailing whitespace. The 'git diff' marks it by inserting an escape sequence to switch the color before ^M and another escape sequence to reset to color after ^M. This breaks the CRLF combination apart, so that the pager does not process it as a combined CRLF sequence; it displays the lone CR as ^M.

It is easy to achieve the opposite effect, i.e., that ^M is not displayed. For example with these lines in .git/info/attributes or .gitattributes:

*.cpp whitespace=trailing-space,cr-at-eol,indent-with-non-tab,space-before-tab *.h whitespace=trailing-space,cr-at-eol,indent-with-non-tab,space-before-tab

Note the cr-at-eol. (There may be shorter versions to achieve a similar effect.)

-- Hannes