test-http-bad-server: replace the default 65537 value in output This is the default block value that we use here and it make the output overall less readable. So we replace it with `~` Differential Revision: https://phab.mercurial-scm.org/D12046

test-http-bad-server: refactor the reading logic to avoid early return Our ultimate goal is to add another way to define the connection needs to be closed. To do so, we need the "read" code to be more unified. Differential Revision: https://phab.mercurial-scm.org/D12045

test-http-bad-server: factor code dealing with "read" in the new object This will make sure both `read` and `readline` do the same processing and make it simpler to update that processing in the future. Differential Revision: https://phab.mercurial-scm.org/D12044

test-http-bad-server: factor code dealing with "write" in the new object This will make sure both `sendall` and `write` do the same processing and make it simpler to update that processing in the future. Differential Revision: https://phab.mercurial-scm.org/D12043

test-http-bad-server: unify log printing for `sendall` and `write` The `write` function was logging before calling the function while the `sendall` function were logging after calling the function. We align the `write` behavior on the `sendall` behavior before unifying the code. Differential Revision: https://phab.mercurial-scm.org/D12042

test-http-bad-server: track close condition in an object In order to make the logic more advanced, we need to unify it. To unify it, we introduce a small object that will be responsible for tracking and enforcing "premature socket close" conditions for both proxy object (socketproxy and fileobjectproxy). More logic will be moved into the object in later changesets. Differential Revision: https://phab.mercurial-scm.org/D12041

test-http-bad-server: use more readable name for variable This make the code more accessible overall. Differential Revision: https://phab.mercurial-scm.org/D12040

test-http-bad-server: align output by using `;` This is the only message using a `,` instead of `;` and that seems unintentional. I am unifying the message before unigying the code. Differential Revision: https://phab.mercurial-scm.org/D12039

test-http-bad-server: highlight each test with section Small "documentation" change to highlight each individual tests better. Differential Revision: https://phab.mercurial-scm.org/D12038

test-http-bad-server: rename config to use `-` This make things much more readable. Differential Revision: https://phab.mercurial-scm.org/D12037

test-http-bad-server: move the extension in `testlib` This seems like a better location for it. Differential Revision: https://phab.mercurial-scm.org/D12036

requirements: remove the `localrepo.supportedformat` attribute It is not longer used anywhere. Differential Revision: https://phab.mercurial-scm.org/D12035

requirements: sort _basesupported This will make the next changeset clearer. Differential Revision: https://phab.mercurial-scm.org/D12034

requirements: move the comment about manifestv2 in the module This is about requirements, so lets put it into the requirements module. We are about to remove code it was previously attached too. Differential Revision: https://phab.mercurial-scm.org/D12033

stream-clone: add a explicit set list requirements relevant to stream clone This set explicitly lists all the requirements that "stream clone" will preserve. Any other one will not be preserved. The role of listing the relevant one was previously filled by `repo.supportedformat`, but it seems clearer to use that such global and explicit set. The `repo.supportedformat` attribute will be cleaned up in a later changeset The true meaning of `repo.supportedformat` vs `repo._basesupported` was lost over time so, the content is currently bad. For example, `dirstate-v2` is currently considered relevant to the stream clone, or internal phase is missing. We kept the same content in this changeset and we will fix them later. Differential Revision: https://phab.mercurial-scm.org/D12032