Merge branch 'ss/submodule-summary-in-c' into seen

Yet another subcommand of "git submodule" is getting rewritten in C.

* ss/submodule-summary-in-c:
  submodule: port submodule subcommand 'summary' from shell to C
  t7421: introduce a test script for verifying 'summary' output
  submodule: rename helper functions to avoid ambiguity
  submodule: remove extra line feeds between callback struct and macro
  submodule: expose the '--for-status' option of summary

Author: gitster

Documentation/git-submodule.txt

@@ -190,7 +190,7 @@ set-url [--] <path> <newurl>::
 	automatically synchronize the submodule's new remote URL
 	configuration.
 
-summary [--cached|--files] [(-n|--summary-limit) <n>] [commit] [--] [<path>...]::
+summary [--cached|--files] [--for-status] [(-n|--summary-limit) <n>] [commit] [--] [<path>...]::
 	Show commit summary between the given commit (defaults to HEAD) and
 	working tree/index. For a submodule in question, a series of commits
 	in the submodule between the given super project commit and the
@@ -309,6 +309,12 @@ OPTIONS
 	compares the commit in the index with that in the submodule HEAD
 	when this option is used.
 
+--for-status::
+	This option is only valid for the summary command. This command
+	skips the submodules with `submodule.<name>.ignore` set to `all`
+	in the `.gitmodules` or `.git/config`. The configuration in
+	`.git/config` overrides the configuration in `.gitmodules`.
+
 -n::
 --summary-limit::
 	This option is only valid for the summary command.