graft: move `if continue` to elif and add new line This will make upcoming patch where we introduce a new elif for the abort case more readable. Also added a new line before the if-else starts. Differential Revision: https://phab.mercurial-scm.org/D3752

graft: start storing new nodes formed in graftstate This patch starts storing the new nodes formed during the ongoing graft operation in the graftstate. We need the list of new nodes formed while implmenting `graft --abort` which will strip out the new nodes. Differential Revision: https://phab.mercurial-scm.org/D3751

show: use filter() function to strip "tip" tag Before, an empty tag "" was inserted in place of "tip", resulting in double spaces.

templater: extend filter() to accept template expression for emptiness test This utilizes the pass-by-name nature of template arguments.

templater: introduce filter() function to remove empty items from list The primary use case is to filter out "tip" from a list of tags.

templater: fix truth testing of integer 0 taken from a list/dict Broken at f9c426385853. bool(python_value) shouldn't be used here since an integer 0 has to be truthy for backward compatibility.

formatter: look for template symbols from the associated name Otherwise symbolsused() would fail if a named template is specified with -T.

py3: add b'' prefixes in tests/test-obsolete-divergent.t This makes the test pass on Python 3. # skip-blame because just b'' prefixes. Differential Revision: https://phab.mercurial-scm.org/D3832

py3: use stringutil.pprint() to print NoneType Before this patch, when running test-debugcommands.t, we get a TypeError because NoneType can't be converted into bytes. This patch uses stringutil.pprint() to print the ui._colormode. We are now close to getting test-debugcommands.t passing on Python 3. Differential Revision: https://phab.mercurial-scm.org/D3831

rebase: make dry-run return 1 or 0 according to result In dry-run mode, if there is no conflict return 0, if any then return 1 Differential Revision: https://phab.mercurial-scm.org/D3829

relink: use context manager for lock management

censor: use context manager for lock management

templater: remove redundant member variables from templater class We no longer need them since the engine is instantiated in __init__().

templater: resurrect cache of engine instance The engine-level cache was effectively disabled at 48289eafb37d "templater: drop extension point of engine classes (API)" by mistake, which made template rendering quite slow. Spotted by Martin von Zweigbergk.