From: Philip Oakley Date: Sun, 07 Apr 2019 22:23:55 GMT Subject: Re: [PATCH 2/2] describe doc: remove '7-char' abbreviation reference Message-ID: <44d40686-e72a-43dd-4798-b02f41ce92ae@iee.org> In-Reply-To: <87bm1ha8ek.fsf@evledraar.gmail.com> Hi Ævar On 07/04/2019 21:05, Ævar Arnfjörð Bjarmason wrote: > On Sat, Apr 06 2019, Philip Oakley wrote: > >> While the minimum is 7-char, the unambiguous length can be longer. >> >> Signed-off-by: Philip Oakley >> --- >> noticed while looking int the Git-for-Windows patch thicket - >> was looking for the ~n^m style! >> --- >> Documentation/git-describe.txt | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt >> index ccdc5f83d6..a88f6ae2c6 100644 >> --- a/Documentation/git-describe.txt >> +++ b/Documentation/git-describe.txt >> @@ -139,7 +139,7 @@ at the end. >> >> The number of additional commits is the number >> of commits which would be displayed by "git log v1.0.4..parent". >> -The hash suffix is "-g" + 7-char abbreviation for the tip commit >> +The hash suffix is "-g" + unambiguous abbreviation for the tip commit >> of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`). >> The "g" prefix stands for "git" and is used to allow describing the version of >> a software depending on the SCM the software is managed with. This is useful > Both the old/new version are subtly wrong. Whether the new one is better > is another matter. > > First, there's more places we mention the now-incorrect 7 characters, at > least these (one of which you're fixing). Found by grepping for ' 7 ' > and '7.*abbr': > > Documentation/git-branch.txt-181---abbrev=:: > Documentation/git-branch.txt-182- Alter the sha1's minimum display length in the output listing. > Documentation/git-branch.txt:183: The default value is 7 and can be overridden by the `core.abbrev` > Documentation/git-branch.txt-184- config option. > Documentation/git-describe.txt-65---abbrev=:: > Documentation/git-describe.txt:66: Instead of using the default 7 hexadecimal digits as the > Documentation/git-describe.txt-67- abbreviated object name, use digits, or as many digits > Documentation/git-ls-tree.txt-93-Object size identified by is given in bytes, and right-justified > Documentation/git-ls-tree.txt:94:with minimum width of 7 characters. Object size is given only for blobs > Documentation/git-ls-tree.txt-95-(file) entries; for other entries `-` character is used in place of size. > Documentation/gittutorial-2.txt-44- > Documentation/gittutorial-2.txt:45:What are the 7 digits of hex that Git responded to the commit with? > Documentation/gittutorial-2.txt-46- > [...] > Documentation/gittutorial-2.txt-52-name), and that the contents of a Git object will never change (since > Documentation/gittutorial-2.txt:53:that would change the object's name as well). The 7 char hex strings > Documentation/gittutorial-2.txt-54-here are simply the abbreviation of such 40 character long strings. > > It was never correct that we'd pick 7 characters, we'd *try* that before > e6c587c733 ("abbrev: auto size the default abbreviation", 2016-09-30) > but would pick a longer one if it was unambiguous. > > Whereas "unambiguous abbreviation" isn't correct either, and arguably > less correct. At least 7 is what we *still* pick as a fallback in lieu > of the auto-sizing, but just "unambiguous abbreviation" implies that in > a repo with some 10 objects we might show just one character, or that > we'd post-e6c587c733 pick say 7 characters in a repository where it *is* > unambiguous but where we've auto-sized to 12. > > I've been meaning to follow-up on > https://public-inbox.org/git/20190204161217.20047-1-avarab@gmail.com/ > where I among other things wanted to just have these instances all say > "commits will be abbreviated as described in XYZ in linkgit:" > and summarize what happens there. > > I don't mind if this goes in, I mainly wrote this E-Mail as a brain dump > since it jolted my memory on the topic, and so that I could dig it up > later & see how I intended to follow-up on those #leftoverbits I had had a look at most of the other '7 ' references and decided that most of those I saw were about the minimum abbreviation settings, but it looks like I maybe missed a few - like the gittutorials.  I was aware that I was being slightly economical with the truth, but was just looking for a way of implying 'variable length' and I punted on the long explanation as the particular reference was way down the document. If anyone has a suggestion for a better phrase I'd be happy And I could add it to the tutorials as well). Philip (added Junio, given his follow up email, though we still need a term for this.)