record: allow splitting of hunks by manually editing patches
It is possible that unrelated changes in a file are on sequential lines. The
current record extension does not allow these to be committed independently.
An example use case for this is in software development for deeply embedded
real-time systems. In these environments, it is not always possible to use a
debugger (due to time-constraints) and hence inline UART-based printing is
often used. When fixing a bug in a module, it is often convenient to add a
large number of 'printf's (linked to the UART via a custom fputc) to the module
in order to work out what is going wrong. printf is a very slow function (and
also variadic so somewhat frowned upon by the MISRA standard) and hence it is
highly undesirable to commit these lines to the repository. If only a partial
fix is implemented, however, it is desirable to commit the fix without deleting
all of the printf lines. This is also simplifies removal of the printf lines
as once the final fix is committed, 'hg revert' does the rest. It is likely
that the printf lines will be very near the actual fix, so being able to split
the hunk is very useful in this case.
There were two alternatives I considered for the user interface. One was to
manually edit the patch, the other to allow a hunk to be split into individual
lines for consideration. The latter option would require a significant
refactor of the record module and is less flexible. While the former is
potentially more complicated to use, this is a feature that is likely to only
be used in certain exceptional cases (such as the use case proposed above) and
hence I felt that the complexity would not be a considerable issue.
I've also written a follow-up patch that refactors the 'prompt' code to base
everything on the choices variable. This tidies up and clarifies the code a
bit (removes constructs like 'if ret == 7' and removes the 'e' option from the
file scope options as it's not relevant there. It's not really a necessity, so
I've excluded it from this submission for now, but I can send it separately if
there's a desire and it's on bitbucket (see below) in the meantime.
Possible future improvements include:
* Tidying up the 'prompt' code to base everything on the choices variable.
This would allow entries to be removed from the prompt as currently 'e' is
offered even for entire file patches, which is currently unsupported.
* Allowing the entire file (or even multi-file) patch to be edited manually:
this would require quite a large refactor without much benefit, so I decided
to exclude it from the initial submission.
* Allow the option to retry if a patch fails to apply (this is what Git does).
This would require quite a bit of refactoring given the current 'hg record'
implementation, so it's debatable whether it's worth it.
Output is similar to existing record user interface except that an additional
option ('e') exists to allow manual editing of the patch. This opens the
user's configured editor with the patch. A comment is added to the bottom of
the patch explaining what to do (based on Git's one).
A large proportion of the changeset is test-case changes to update the options
reported by record (Ynesfdaq? instead of Ynsfdaq?). Functional changes are in
record.py and there are some new test cases in test-record.t.
# If you want to change PREFIX, do not just edit it below. The changed
# value wont get passed on to recursive make calls. You should instead
# override the variable on the command like:
#
# % make PREFIX=/opt/ install
PREFIX=/usr/local
export PREFIX
PYTHON=python
PURE=
PYFILES:=$(shell find mercurial hgext doc -name '*.py')
DOCFILES=mercurial/help/*.txt
help:
@echo 'Commonly used make targets:'
@echo ' all - build program and documentation'
@echo ' install - install program and man pages to PREFIX ($(PREFIX))'
@echo ' install-home - install with setup.py install --home=HOME ($(HOME))'
@echo ' local - build for inplace usage'
@echo ' tests - run all tests in the automatic test suite'
@echo ' test-foo - run only specified tests (e.g. test-merge1.t)'
@echo ' dist - run all tests and create a source tarball in dist/'
@echo ' clean - remove files created by other targets'
@echo ' (except installed files or dist source tarball)'
@echo ' update-pot - update i18n/hg.pot'
@echo
@echo 'Example for a system-wide installation under /usr/local:'
@echo ' make all && su -c "make install" && hg version'
@echo
@echo 'Example for a local installation (usable in this directory):'
@echo ' make local && ./hg version'
all: build doc
local:
$(PYTHON) setup.py $(PURE) build_py -c -d . build_ext -i build_mo
$(PYTHON) hg version
build:
$(PYTHON) setup.py $(PURE) build
doc:
$(MAKE) -C doc
clean:
-$(PYTHON) setup.py clean --all # ignore errors from this command
find . \( -name '*.py[cdo]' -o -name '*.so' \) -exec rm -f '{}' ';'
rm -f $(addprefix mercurial/,$(notdir $(wildcard mercurial/pure/*.py)))
rm -f MANIFEST MANIFEST.in tests/*.err
rm -rf build mercurial/locale
$(MAKE) -C doc clean
install: install-bin install-doc
install-bin: build
$(PYTHON) setup.py $(PURE) install --root="$(DESTDIR)/" --prefix="$(PREFIX)" --force
install-doc: doc
cd doc && $(MAKE) $(MFLAGS) install
install-home: install-home-bin install-home-doc
install-home-bin: build
$(PYTHON) setup.py $(PURE) install --home="$(HOME)" --force
install-home-doc: doc
cd doc && $(MAKE) $(MFLAGS) PREFIX="$(HOME)" install
MANIFEST-doc:
$(MAKE) -C doc MANIFEST
MANIFEST.in: MANIFEST-doc
hg manifest | sed -e 's/^/include /' > MANIFEST.in
echo include mercurial/__version__.py >> MANIFEST.in
sed -e 's/^/include /' < doc/MANIFEST >> MANIFEST.in
dist: tests dist-notests
dist-notests: doc MANIFEST.in
TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py -q sdist
check: tests
tests:
cd tests && $(PYTHON) run-tests.py $(TESTFLAGS)
test-%:
cd tests && $(PYTHON) run-tests.py $(TESTFLAGS) $@
update-pot: i18n/hg.pot
i18n/hg.pot: $(PYFILES) $(DOCFILES)
$(PYTHON) i18n/hggettext mercurial/commands.py \
hgext/*.py hgext/*/__init__.py \
mercurial/fileset.py mercurial/revset.py \
mercurial/templatefilters.py mercurial/templatekw.py \
mercurial/filemerge.py \
$(DOCFILES) > i18n/hg.pot
# All strings marked for translation in Mercurial contain
# ASCII characters only. But some files contain string
# literals like this '\037\213'. xgettext thinks it has to
# parse them even though they are not marked for translation.
# Extracting with an explicit encoding of ISO-8859-1 will make
# xgettext "parse" and ignore them.
echo $(PYFILES) | xargs \
xgettext --package-name "Mercurial" \
--msgid-bugs-address "<mercurial-devel@selenic.com>" \
--copyright-holder "Matt Mackall <mpm@selenic.com> and others" \
--from-code ISO-8859-1 --join --sort-by-file --add-comments=i18n: \
-d hg -p i18n -o hg.pot
$(PYTHON) i18n/posplit i18n/hg.pot
%.po: i18n/hg.pot
msgmerge --no-location --update $@ $^
.PHONY: help all local build doc clean install install-bin install-doc \
install-home install-home-bin install-home-doc dist dist-notests tests \
update-pot