Merge branch 'fc/transport-helper-waitpid' into pu

* fc/transport-helper-waitpid:
  transport-helper: check if remote helper is alive
  run-command: add new check_command helper
Merge branch 'jk/diffcore-break-divzero' into pu

* jk/diffcore-break-divzero:
  diffcore-break: don't divide by zero
Merge branch 'jk/bisect-prn-unsigned' into pu

* jk/bisect-prn-unsigned:
  bisect: avoid signed integer overflow
Merge branch 'jk/set-upstream-error-cases' into pu

* jk/set-upstream-error-cases:
  branch: give advice when tracking start-point is missing
  branch: mention start_name in set-upstream error messages
  branch: improve error message for missing --set-upstream-to ref
  branch: factor out "upstream is not a branch" error messages
  t3200: test --set-upstream-to with bogus refs
Merge branch 'po/help-guides' into pu

* po/help-guides:
  doc: include --guide option description for "git help"
  help: mention -a and -g option, and 'git help <concept>' usage.
  builtin/help.c: add list_common_guides_help() function
  builtin/help.c: add --guide option
  builtin/help.c: split "-a" processing into two