The function fchown is annotated with warn_unused_result. As
formerly used in the code, it would emit a compiler warning
```warning: ignoring return value of ‘fchown’, declared with
attribute warn_unused_result [-Wunused-result]```
This commit notes the return value and emits appropriate error/logging
messages if the call fails, creating more traceable results and
satisfying the compiler.
New implementation of migration code within the history_t class will
copy the contents of the old fish_history found in the config directory
to its new location in the data directory. The old file is left intact.
This is done only in the event that a fish_history is not already found in
the data directory ($XDG_DATA_HOME/fish or ~/.local/share/fish).
Add new functions path_get_data and path_create_data which parallel existing
functions path_get_config and path_create_data. The new functions refer to
XDG_DATA_HOME, if it is defined, or ./local/share if not.
Modify history_filename to use the new function path_get_data.
As a consequence, fish_history will now be located in XDG_DATA_HOME,
not XDG_CONFIG_HOME.
Note that these changes mirror what is already used in
fish-shell/share/tools/create_manpage_completions.py, which stores the
completions in XDG_DATA_HOME
This change matches recommendations in the xdg basedir spec at
http://standards.freedesktop.org/basedir-spec/basedir-spec-0.7.html
($XDG_DATA_HOME defines the base directory relative to which user specific data
files should be stored. If $XDG_DATA_HOME is either not set or empty, a default
equal to $HOME/.local/share should be used.)
It addresses suggestions from the following issues:
1. Don't put history in $XDG_CONFIG_HOME (closes#744)
https://github.com/fish-shell/fish-shell/issues/744
2. Fish is placing non-config files in $XDG_CONFIG_HOME #1257https://github.com/fish-shell/fish-shell/issues/1257
3. Move non-config data out of $XDG_CONFIG_HOME #1669https://github.com/fish-shell/fish-shell/issues/1669
This change moves source files into a src/ directory,
and puts object files into an obj/ directory. The Makefile
and xcode project are updated accordingly.
Fixes#1866
