[PATCH v7 0/9] submodule: improve robustness of path handling

This series improves the robustness of path handling by 'git submodule' by:

* detecting submodule URLs that will result in non-sensical submodule origin URLs

* improving handling of various kinds of relative superproject origin URLs

* improving handling of various kinds of denormalized superproject origin URLs

This series differs from v5 in the following ways, by:

* Adding a more extensive set of failure tests to illustrate the conditions 
being addressed.

* Modifying the ../ processing loop in resolve_relative_url to exclude the 
'invariant' parts of absolute URLs from relative URL processing and thereby 
enable earlier and more accurate detection of edits that are going to 
produce a non-sensical output.

* Simplifying relative superproject origin URL support, by taking advantage of
the modifications above.

* Adding support for normalizing denormalized superproject origin URLs.

* Adding some additional regression tests to help guard against 
unintended regressions by this series.

* Improving the source code comments to better explain the purpose
of various code functions and code blocks

This series differs from v6 by applying the fix in 8/9 to a wider set of tests.

Each patch in the series has been regression tested against the following tests:

   t2013-checkout-submodule.sh
   t2103-update-index-ignore-missing.sh
   t2105-update-index-gitfile.sh
   t2201-add-update-typechange.sh
   t3000-ls-files-others.sh
   t3030-merge-recursive.sh
   t3404-rebase-interactive.sh
   t4027-diff-submodule.sh
   t4041-diff-submodule-option.sh
   t4134-apply-submodule.sh
   t5526-fetch-submodules.sh
   t5531-deep-submodule-push.sh
   t6008-rev-list-submodule.sh
   t7003-filter-branch.sh
   t7400-submodule-basic.sh
   t7401-submodule-summary.sh
   t7402-submodule-rebase.sh
   t7403-submodule-sync.sh
   t7405-submodule-merge.sh
   t7406-submodule-update.sh
   t7407-submodule-foreach.sh
   t7408-submodule-reference.sh
   t7506-status-submodule.sh
   t7508-status.sh
   t7610-mergetool.sh
   t9300-fast-import.sh
   t9350-fast-export.sh

which are the tests that match a grep search for submodule.

Jon Seymour (9):
  submodule: additional regression tests for relative URLs
  submodule: document failure to detect invalid submodule URLs
  submodule: document failure to handle relative superproject origin
    URLs
  submodule: document failure to handle improperly normalized remote
    origin URLs
  submodule: extract normalize_path into standalone function
  submodule: fix detection of invalid submodule URL
  submodule: fix sync handling of relative superproject origin URLs
  submodule: fix handling of denormalized superproject origin URLs
  submodule: fix normalization to handle repeated ./

 git-submodule.sh             | 118 +++++++++++++----
 t/t7400-submodule-basic.sh   | 297 ++++++++++++++++++++++++++++++++++++++++++-
 t/t7403-submodule-sync.sh    |  97 +++++++++++++-
 t/t7406-submodule-update.sh  |  16 ++-
 t/t7407-submodule-foreach.sh |  14 +-
 t/t7506-status-submodule.sh  |  10 +-
 6 files changed, 504 insertions(+), 48 deletions(-)