Merge branch 'maint'

* maint: commit: discard index after setting up partial commit filter-branch: handle filenames that need quoting diff: Fix miscounting of --check output hg-to-git: fix parent analysis mailinfo: feed only one line to handle_filter() for QP input diff.c: add "const" qualifier to "char *cmd" member of "struct ll_diff_driver" Add "const" qualifier to "char *excludes_file". Add "const" qualifier to "char *editor_program". Add "const" qualifier to "char *pager_program". config: add 'git_config_string' to refactor string config variables. diff.c: remove useless check for value != NULL fast-import: check return value from unpack_entry() Validate nicknames of remote branches to prohibit confusing ones diff.c: replace a 'strdup' with 'xstrdup'. diff.c: fixup garding of config parser from value=NULL