[PATCH v3 0/5] Bundle URIs II: git clone --bundle-uri

This is the second series building the bundle URI feature as discussed in the previous series that added the design document [1]. This series does not modify the design document, so the patches are independent and can be applied to the latest 'master'.

[1] https://lore.kernel.org/git/pull.1248.v3.git.1658757188.gitgitgadget@gmail.com

This series brings in just enough logic that we can bootstrap clones from a single bundle using git clone --bundle-uri=<X>.

 * Patch 1 adds a 'get' capability to 'git remote-https' which allows
   downloading the contents of a URI to a local file.
 * Patch 2 creates basic file-copy logic within a new bundle-uri.c file. It
   is not used until patch 3.
 * Patch 3 creates the git clone --bundle-uri=<X> option, allowing Git to
   bootstrap a clone from a bundle, but get the remaining objects from the
   origin URL. (As of this patch, it only accepts a filename.)
 * Patch 4 extends the git clone --bundle-uri=<X> option to allow file://
   and https:// URIs.
 * Patch 5 is a CLI helper to avoid using --bundle-uri and --depth at the
   same time in git clone.

As outlined in [1], the next steps after this are:

 1. Allow parsing a bundle list as a config file at the given URI. The
    key-value format is unified with the protocol v2 verb (coming in (3)).
    [2]
 2. Implement the protocol v2 verb, re-using the bundle list logic from (2).
    Use this to auto-discover bundle URIs during 'git clone' (behind a
    config option). [3]
 3. Implement the 'creationToken' heuristic, allowing incremental 'git
    fetch' commands to download a bundle list from a configured URI, and
    only download bundles that are new based on the creation token values.
    [4]

I have prepared some of this work as pull requests on my personal fork so curious readers can look ahead to where we are going:

[2] https://github.com/derrickstolee/git/pull/20

[3] https://github.com/derrickstolee/git/pull/21

[4] https://github.com/derrickstolee/git/pull/22

Note: this series includes some code pulled out of the first series [1], and
in particular the git fetch --bundle-uri=<X> option is removed. The
intention was to replace that with git bundle fetch <X>, but that conflicts
with the work to refactor how subcommands are parsed. The git bundle fetch
subcommand could be added later for maximum flexibility on the client side,
but we can also move forward without it.

Updates in v3 =============

 * The protocol matching for "http://", "https://", and "file://" now
   uniformly include the "//" portion and are case-sensitive.

Updates in v2 =============

 * Several typos or small tweaks. See the range-diff for details.

Thanks, -Stolee

Derrick Stolee (5):
  remote-curl: add 'get' capability
  bundle-uri: create basic file-copy logic
  clone: add --bundle-uri option
  bundle-uri: add support for http(s):// and file://
  clone: --bundle-uri cannot be combined with --depth

 Documentation/git-clone.txt         |   7 ++
 Documentation/gitremote-helpers.txt |   9 ++
 Makefile                            |   1 +
 builtin/clone.c                     |  18 +++
 bundle-uri.c                        | 168 ++++++++++++++++++++++++++++
 bundle-uri.h                        |  14 +++
 remote-curl.c                       |  28 +++++
 t/t5557-http-get.sh                 |  39 +++++++
 t/t5558-clone-bundle-uri.sh         |  81 ++++++++++++++
 t/t5606-clone-options.sh            |   8 ++
 10 files changed, 373 insertions(+)
 create mode 100644 bundle-uri.c
 create mode 100644 bundle-uri.h
 create mode 100755 t/t5557-http-get.sh
 create mode 100755 t/t5558-clone-bundle-uri.sh

base-commit: e72d93e88cb20b06e88e6e7d81bd1dc4effe453f
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1300%2Fderrickstolee%2Fbundle-redo%2Fclone-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1300/derrickstolee/bundle-redo/clone-v3
Pull-Request: https://github.com/gitgitgadget/git/pull/1300

Range-diff vs v2:

 1:  4df4a1d679a = 1:  4df4a1d679a remote-curl: add 'get' capability
 2:  6a6f1a04889 = 2:  6a6f1a04889 bundle-uri: create basic file-copy logic
 3:  00debaf6e77 = 3:  00debaf6e77 clone: add --bundle-uri option
 4:  e4f2dcc7a45 ! 4:  66a1ce40451 bundle-uri: add support for http(s):// and file://
     @@ bundle-uri.c: static int find_temp_filename(struct strbuf *name)
      +	struct strbuf line = STRBUF_INIT;
      +	int found_get = 0;
      +
     -+	strvec_pushl(&cp.args, "git-remote-https", "origin", uri, NULL);
     ++	strvec_pushl(&cp.args, "git-remote-https", uri, NULL);
      +	cp.in = -1;
      +	cp.out = -1;
      +
     @@ bundle-uri.c: static int find_temp_filename(struct strbuf *name)
      +{
      +	const char *out;
      +
     -+	if (istarts_with(uri, "https:") ||
     -+	    istarts_with(uri, "http:"))
     ++	if (starts_with(uri, "https:") ||
     ++	    starts_with(uri, "http:"))
      +		return download_https_uri_to_file(filename, uri);
      +
     -+	if (!skip_prefix(uri, "file://", &out))
     -+		out = uri;
     ++	if (skip_prefix(uri, "file://", &out))
     ++		uri = out;
      +
      +	/* Copy as a file */
     -+	return copy_file(filename, out, 0);
     ++	return copy_file(filename, uri, 0);
       }
       
       static int unbundle_from_file(struct repository *r, const char *file)
 5:  acee1fae027 = 5:  ed76d84c5a7 clone: --bundle-uri cannot be combined with --depth