Re: [PATCH 3/5] protocol-capabilities.txt: clarify "allow-x-sha1-in-want" re SHA-256

[Derrick Stolee <stolee@gmail.com>]

On 8/14/2020 8:21 AM, Martin Ågren wrote:
> Two of our extensions contain "sha1" in their names, but that's
> historical. The "want"s will take object names that are not necessarily
> SHA-1s. Make this clear, but also make it clear how there's still just
> one correct hash algo: These extensions don't somehow make the "want"s
> take object names derived using *any* hash algorithm.
> 
> Signed-off-by: Martin Ågren <martin.agren@gmail.com>
> ---
>  Documentation/technical/protocol-capabilities.txt | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt
> index 36ccd14f97..47f1b30090 100644
> --- a/Documentation/technical/protocol-capabilities.txt
> +++ b/Documentation/technical/protocol-capabilities.txt
> @@ -324,15 +324,18 @@ allow-tip-sha1-in-want
>  ----------------------
>  
>  If the upload-pack server advertises this capability, fetch-pack may
> -send "want" lines with SHA-1s that exist at the server but are not
> -advertised by upload-pack.
> +send "want" lines with object names that exist at the server but are not
> +advertised by upload-pack. (Note that the name of the capability
> +contains "sha1", but that it's more general than that: in SHA-1
> +repositories, the "want" lines provide SHA-1 values, but in SHA-256
> +repositories, they provide SHA-256 values.)
>  
>  allow-reachable-sha1-in-want
>  ----------------------------
>  
>  If the upload-pack server advertises this capability, fetch-pack may
> -send "want" lines with SHA-1s that exist at the server but are not
> -advertised by upload-pack.
> +send "want" lines with object names that exist at the server but are not
> +advertised by upload-pack. (Same remark about "sha1" as above.)

This "as above" is brittle to future changes. I think it
could be improved with

	(As in "allow-tip-sha1-in-want", the "sha1" in this capability
	refers to object names, not the hash algorithm chosen for the
	repository.)

Or, just repeat the same note again.

Thanks,
-Stolee