bundle2: only emit compressed chunks if they have data This is similar to 58467204cac0. Not all calls into the compressor return compressed data, as the compressor may buffer compressed output internally. It is cheaper to check for empty chunks than to send empty chunks through the generator. When generating a gzip-v2 bundle of the mozilla-unified repo, this change results in 50,093 empty chunks not being sent through the generator (out of 1,902,996 total input chunks).

color: add some documentation for custom terminfo codes

color: debugcolor should emit the user-defined colors This also fixes a long-standing bug that reversed the sense of the color name and the label used to print it, which was never relevant before.

color: ignore effects missing from terminfo If terminfo mode is in effect, and an effect is used which is missing from the terminfo database, simply silently ignore the request, leaving the output unaffected rather than causing a crash.

color: allow for user-configurable terminfo codes for effects If the entry in the terminfo database for your terminal is missing some attributes, it should be possible to create them on the fly without resorting to just making them a color. This change allows you to have [color] terminfo.<effect> = <code> where <effect> might be something like "dim" or "bold", and <code> is the escape sequence that would otherwise have come from a call to tigetstr(). If an escape character is needed, use "\E". Any such settings will override attributes that are present in the terminfo database.

update: warn if cwd was deleted During update directories are deleted as soon as they have no entries. But if current working directory is deleted then it cause problems in complex commands like 'hg split'. This commit adds a warning that will help users figure the problem faster.

parsers: avoid PySliceObject cast on Python 3 PySlice_GetIndicesEx() accepts a PySliceObject* on Python 2 and a PyObject* on Python 3. Casting to PySliceObject* on Python 3 was yielding a compiler warning. So stop doing that. With this patch, I no longer see any compiler warnings when building the core extensions for Python 3!

bdiff: include util.h Without this, IS_PY3K isn't define and the preprocessor uses the incorrect module loading code, causing the module fail to load at run-time. After this patch, all our C extensions (except for watchman's) appear to import correctly in Python 3!

parsers: alias more PyInt* symbols on Python 3 I feel dirty for having to do this. But this is currently our approach for dealing with PyInt -> PyLong in Python 3 for this file. This removes a ton of compiler warnings by fixing unresolved symbols.

manifest: use PyVarObject_HEAD_INIT More appeasing the Python 3 and compiler overlords. The code is equivalent.