merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 95 insertions, 0 deletions

diff --git a/third_party/git/Documentation/git-sh-setup.txt b/third_party/git/Documentation/git-sh-setup.txt
new file mode 100644
index 000000000000..8632612c31d0
--- /dev/null
+++ b/third_party/git/Documentation/git-sh-setup.txt
@@ -0,0 +1,95 @@
+git-sh-setup(1)
+===============
+
+NAME
+----
+git-sh-setup - Common Git shell script setup code
+
+SYNOPSIS
+--------
+[verse]
+'. "$(git --exec-path)/git-sh-setup"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git sh-setup' scriptlet is designed to be sourced (using
+`.`) by other shell scripts to set up some variables pointing at
+the normal Git directories and a few helper shell functions.
+
+Before sourcing it, your script should set up a few variables;
+`USAGE` (and `LONG_USAGE`, if any) is used to define message
+given by `usage()` shell function.  `SUBDIRECTORY_OK` can be set
+if the script can run from a subdirectory of the working tree
+(some commands do not).
+
+The scriptlet sets `GIT_DIR` and `GIT_OBJECT_DIRECTORY` shell
+variables, but does *not* export them to the environment.
+
+FUNCTIONS
+---------
+
+die::
+	exit after emitting the supplied error message to the
+	standard error stream.
+
+usage::
+	die with the usage message.
+
+set_reflog_action::
+	Set `GIT_REFLOG_ACTION` environment to a given string (typically
+	the name of the program) unless it is already set.  Whenever
+	the script runs a `git` command that updates refs, a reflog
+	entry is created using the value of this string to leave the
+	record of what command updated the ref.
+
+git_editor::
+	runs an editor of user's choice (GIT_EDITOR, core.editor, VISUAL or
+	EDITOR) on a given file, but error out if no editor is specified
+	and the terminal is dumb.
+
+is_bare_repository::
+	outputs `true` or `false` to the standard output stream
+	to indicate if the repository is a bare repository
+	(i.e. without an associated working tree).
+
+cd_to_toplevel::
+	runs chdir to the toplevel of the working tree.
+
+require_work_tree::
+	checks if the current directory is within the working tree
+	of the repository, and otherwise dies.
+
+require_work_tree_exists::
+	checks if the working tree associated with the repository
+	exists, and otherwise dies.  Often done before calling
+	cd_to_toplevel, which is impossible to do if there is no
+	working tree.
+
+require_clean_work_tree <action> [<hint>]::
+	checks that the working tree and index associated with the
+	repository have no uncommitted changes to tracked files.
+	Otherwise it emits an error message of the form `Cannot
+	<action>: <reason>. <hint>`, and dies.  Example:
++
+----------------
+require_clean_work_tree rebase "Please commit or stash them."
+----------------
+
+get_author_ident_from_commit::
+	outputs code for use with eval to set the GIT_AUTHOR_NAME,
+	GIT_AUTHOR_EMAIL and GIT_AUTHOR_DATE variables for a given commit.
+
+create_virtual_base::
+	modifies the first file so only lines in common with the
+	second file remain. If there is insufficient common material,
+	then the first file is left empty. The result is suitable
+	as a virtual base input for a 3-way merge.
+
+GIT
+---
+Part of the linkgit:git[1] suite