Re: [PATCH] mergetools/meld: improve backwards-compatibiilty when using "--output"

On Sun, Jun 18, 2017 at 8:17 PM, David Aguilar [off-list ref] wrote:

On Sun, Jun 18, 2017 at 05:11:48AM -0400, Samuel Lijin wrote:

quoted

On Sun, Jun 18, 2017 at 3:46 AM, David Aguilar [off-list ref] wrote:

quoted

On Sat, Jun 17, 2017 at 10:11:36AM -0400, Samuel Lijin wrote:

quoted

On Sat, Jun 17, 2017 at 6:24 AM, David Aguilar [off-list ref] wrote:

quoted

Meld 3.16.0 requires a "=" in the --output argument, as it uses
a simple hand-rolled command-line parser.

Newer versions of Meld (3.16.4, and possibly earlier) use
optpaarse, which accepts either "--output <file>" or
"--output=<file>".

Junio, there's an optpaarse -> optparse typo in the commit message
here in case you want to fix that up.

quoted

Do older versions also support both?

No.  When the "--output" option was first added (3.16.0, or possibly
earlier) it used the simpler parser that does not undertand the
"--output <filename>" form.

Much older versions didn't support "--output" at all, so we don't have
to worry about them since we already use the "--output" flag
selectively based on whether or not it's supported.

It sounds like this patch would break versions of Meld that use the
hand-rolled parser, then.

I don't think so.

The whole point of this patch is to make it compatible with the
hand-rolled parser.

Before the patch:

        --output <filename>

After the patch:

        --output=<filename>


The form with "=" (the latter one) is the one that's maximally
compatible.

Please re-read the commit message and patch to verify that this is
indeed true.

Whoops, sorry, yes, you're right. It does still sound like there are
some versions of Meld in the middle that rely on "--output <filename>"
though, that this does break.