add-patch.c: compare oids instead of string literals

Documentation/config/gpg.txt

@@ -34,7 +34,7 @@ gpg.minTrustLevel::
 * `fully`
 * `ultimate`
 
-gpg.ssh.defaultKeyCommand:
+gpg.ssh.defaultKeyCommand::
 	This command that will be run when user.signingkey is not set and a ssh
 	signature is requested. On successful exit a valid ssh public key is
 	expected in the	first line of its output. To automatically use the first
@@ -44,7 +44,7 @@ gpg.ssh.allowedSignersFile::
 	A file containing ssh public keys which you are willing to trust.
 	The file consists of one or more lines of principals followed by an ssh
 	public key.
-	e.g.: user1@example.com,user2@example.com ssh-rsa AAAAX1...
+	e.g.: `user1@example.com,user2@example.com ssh-rsa AAAAX1...`
 	See ssh-keygen(1) "ALLOWED SIGNERS" for details.
 	The principal is only used to identify the key and is available when
 	verifying a signature.

Documentation/git-am.txt

@@ -16,8 +16,9 @@ SYNOPSIS
 	 [--exclude=<path>] [--include=<path>] [--reject] [-q | --quiet]
 	 [--[no-]scissors] [-S[<keyid>]] [--patch-format=<format>]
 	 [--quoted-cr=<action>]
+	 [--empty=(stop|drop|keep)]
 	 [(<mbox> | <Maildir>)...]
-'git am' (--continue | --skip | --abort | --quit | --show-current-patch[=(diff|raw)])
+'git am' (--continue | --skip | --abort | --quit | --show-current-patch[=(diff|raw)] | --allow-empty)
 
 DESCRIPTION
 -----------
@@ -63,6 +64,14 @@ OPTIONS
 --quoted-cr=<action>::
 	This flag will be passed down to 'git mailinfo' (see linkgit:git-mailinfo[1]).
 
+--empty=(stop|drop|keep)::
+	By default, or when the option is set to 'stop', the command
+	errors out on an input e-mail message lacking a patch
+	and stops into the middle of the current am session. When this
+	option is set to 'drop', skip such an e-mail message instead.
+	When this option is set to 'keep', create an empty commit,
+	recording the contents of the e-mail message as its log.
+
 -m::
 --message-id::
 	Pass the `-m` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]),
@@ -191,6 +200,11 @@ default.   You can use `--no-utf8` to override this.
 	the e-mail message; if `diff`, show the diff portion only.
 	Defaults to `raw`.
 
+--allow-empty::
+	After a patch failure on an input e-mail message lacking a patch,
+	create an empty commit with the contents of the e-mail message
+	as its log message.
+
 DISCUSSION
 ----------
 

Documentation/git-clone.txt

@@ -167,10 +167,10 @@ objects from the source repository into a pack in the cloned repository.
 	configuration variables are created.
 
 --sparse::
-	Initialize the sparse-checkout file so the working
-	directory starts with only the files in the root
-	of the repository. The sparse-checkout file can be
-	modified to grow the working directory as needed.
+	Employ a sparse-checkout, with only files in the toplevel
+	directory initially being present.  The
+	linkgit:git-sparse-checkout[1] command can be used to grow the
+	working directory as needed.
 
 --filter=<filter-spec>::
 	Use the partial clone feature and request that the server sends

Documentation/git-fmt-merge-msg.txt

@@ -9,7 +9,7 @@ git-fmt-merge-msg - Produce a merge commit message
 SYNOPSIS
 --------
 [verse]
-'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log]
+'git fmt-merge-msg' [-m <message>] [--into-name <branch>] [--log[=<n>] | --no-log]
 'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log] -F <file>
 
 DESCRIPTION
@@ -44,6 +44,10 @@ OPTIONS
 	Use <message> instead of the branch names for the first line
 	of the log message.  For use with `--log`.
 
+--into-name <branch>::
+	Prepare the merge message as if merging to the branch `<branch>`,
+	instead of the name of the real branch to which the merge is made.
+
 -F <file>::
 --file <file>::
 	Take the list of merged objects from <file> instead of

Documentation/git-format-patch.txt

@@ -18,7 +18,7 @@ SYNOPSIS
 		   [-n | --numbered | -N | --no-numbered]
 		   [--start-number <n>] [--numbered-files]
 		   [--in-reply-to=<message id>] [--suffix=.<sfx>]
-		   [--ignore-if-in-upstream]
+		   [--ignore-if-in-upstream] [--always]
 		   [--cover-from-description=<mode>]
 		   [--rfc] [--subject-prefix=<subject prefix>]
 		   [(--reroll-count|-v) <n>]
@@ -192,6 +192,10 @@ will want to ensure that threading is disabled for `git send-email`.
 	patches being generated, and any patch that matches is
 	ignored.
 
+--always::
+	Include patches for commits that do not introduce any change,
+	which are omitted by default.
+
 --cover-from-description=<mode>::
 	Controls which parts of the cover letter will be automatically
 	populated using the branch's description.

Documentation/git-merge.txt

@@ -12,7 +12,8 @@ SYNOPSIS
 'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
 	[--no-verify] [-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
 	[--[no-]allow-unrelated-histories]
-	[--[no-]rerere-autoupdate] [-m <msg>] [-F <file>] [<commit>...]
+	[--[no-]rerere-autoupdate] [-m <msg>] [-F <file>]
+	[--into-name <branch>] [<commit>...]
 'git merge' (--continue | --abort | --quit)
 
 DESCRIPTION
@@ -76,6 +77,11 @@ The 'git fmt-merge-msg' command can be
 used to give a good default for automated 'git merge'
 invocations. The automated message can include the branch description.
 
+--into-name <branch>::
+	Prepare the default merge message as if merging to the branch
+	`<branch>`, instead of the name of the real branch to which
+	the merge is made.
+
 -F <file>::
 --file=<file>::
 	Read the commit message to be used for the merge commit (in

Documentation/git-repack.txt

@@ -76,8 +76,9 @@ to the new separate pack will be written.
 	linkgit:git-pack-objects[1].
 
 -q::
-	Pass the `-q` option to 'git pack-objects'. See
-	linkgit:git-pack-objects[1].
+--quiet::
+	Show no progress over the standard error stream and pass the `-q`
+	option to 'git pack-objects'. See linkgit:git-pack-objects[1].
 
 -n::
 	Do not update the server information with

Documentation/git-sparse-checkout.txt

@@ -30,28 +30,36 @@ COMMANDS
 'list'::
 	Describe the patterns in the sparse-checkout file.
 
-'init'::
-	Enable the `core.sparseCheckout` setting. If the
-	sparse-checkout file does not exist, then populate it with
-	patterns that match every file in the root directory and
-	no other directories, then will remove all directories tracked
-	by Git. Add patterns to the sparse-checkout file to
-	repopulate the working directory.
+'set'::
+	Enable the necessary config settings
+	(extensions.worktreeConfig, core.sparseCheckout,
+	core.sparseCheckoutCone) if they are not already enabled, and
+	write a set of patterns to the sparse-checkout file from the
+	list of arguments following the 'set' subcommand. Update the
+	working directory to match the new patterns.
 +
-To avoid interfering with other worktrees, it first enables the
-`extensions.worktreeConfig` setting and makes sure to set the
-`core.sparseCheckout` setting in the worktree-specific config file.
+When the `--stdin` option is provided, the patterns are read from
+standard in as a newline-delimited list instead of from the arguments.
 +
-When `--cone` is provided, the `core.sparseCheckoutCone` setting is
-also set, allowing for better performance with a limited set of
-patterns (see 'CONE PATTERN SET' below).
+When `--cone` is passed or `core.sparseCheckoutCone` is enabled, the
+input list is considered a list of directories instead of
+sparse-checkout patterns.  This allows for better performance with a
+limited set of patterns (see 'CONE PATTERN SET' below).  Note that the
+set command will write patterns to the sparse-checkout file to include
+all files contained in those directories (recursively) as well as
+files that are siblings of ancestor directories. The input format
+matches the output of `git ls-tree --name-only`.  This includes
+interpreting pathnames that begin with a double quote (") as C-style
+quoted strings.  This may become the default in the future; --no-cone
+can be passed to request non-cone mode.
 +
-Use the `--[no-]sparse-index` option to toggle the use of the sparse
-index format. This reduces the size of the index to be more closely
-aligned with your sparse-checkout definition. This can have significant
-performance advantages for commands such as `git status` or `git add`.
-This feature is still experimental. Some commands might be slower with
-a sparse index until they are properly integrated with the feature.
+Use the `--[no-]sparse-index` option to use a sparse index (the
+default is to not use it).  A sparse index reduces the size of the
+index to be more closely aligned with your sparse-checkout
+definition. This can have significant performance advantages for
+commands such as `git status` or `git add`.  This feature is still
+experimental. Some commands might be slower with a sparse index until
+they are properly integrated with the feature.
 +
 **WARNING:** Using a sparse index requires modifying the index in a way
 that is not completely understood by external tools. If you have trouble
@@ -60,23 +68,6 @@ to rewrite your index to not be sparse. Older versions of Git will not
 understand the sparse directory entries index extension and may fail to
 interact with your repository until it is disabled.
 
-'set'::
-	Write a set of patterns to the sparse-checkout file, as given as
-	a list of arguments following the 'set' subcommand. Update the
-	working directory to match the new patterns. Enable the
-	core.sparseCheckout config setting if it is not already enabled.
-+
-When the `--stdin` option is provided, the patterns are read from
-standard in as a newline-delimited list instead of from the arguments.
-+
-When `core.sparseCheckoutCone` is enabled, the input list is considered a
-list of directories instead of sparse-checkout patterns. The command writes
-patterns to the sparse-checkout file to include all files contained in those
-directories (recursively) as well as files that are siblings of ancestor
-directories. The input format matches the output of `git ls-tree --name-only`.
-This includes interpreting pathnames that begin with a double quote (") as
-C-style quoted strings.
-
 'add'::
 	Update the sparse-checkout file to include additional patterns.
 	By default, these patterns are read from the command-line arguments,
@@ -93,12 +84,35 @@ C-style quoted strings.
 	cases, it can make sense to run `git sparse-checkout reapply` later
 	after cleaning up affected paths (e.g. resolving conflicts, undoing
 	or committing changes, etc.).
++
+The `reapply` command can also take `--[no-]cone` and `--[no-]sparse-index`
+flags, with the same meaning as the flags from the `set` command, in order
+to change which sparsity mode you are using without needing to also respecify
+all sparsity paths.
 
 'disable'::
 	Disable the `core.sparseCheckout` config setting, and restore the
-	working directory to include all files. Leaves the sparse-checkout
-	file intact so a later 'git sparse-checkout init' command may
-	return the working directory to the same state.
+	working directory to include all files.
+
+'init'::
+	Deprecated command that behaves like `set` with no specified paths.
+	May be removed in the future.
++
+Historically, `set` did not handle all the necessary config settings,
+which meant that both `init` and `set` had to be called.  Invoking
+both meant the `init` step would first remove nearly all tracked files
+(and in cone mode, ignored files too), then the `set` step would add
+many of the tracked files (but not ignored files) back.  In addition
+to the lost files, the performance and UI of this combination was
+poor.
++
+Also, historically, `init` would not actually initialize the
+sparse-checkout file if it already existed.  This meant it was
+possible to return to a sparse-checkout without remembering which
+paths to pass to a subsequent 'set' or 'add' command.  However,
+`--cone` and `--sparse-index` options would not be remembered across
+the disable command, so the easy restore of calling a plain `init`
+decreased in utility.
 
 SPARSE CHECKOUT
 ---------------
@@ -107,7 +121,7 @@ SPARSE CHECKOUT
 It uses the skip-worktree bit (see linkgit:git-update-index[1]) to tell
 Git whether a file in the working directory is worth looking at. If
 the skip-worktree bit is set, then the file is ignored in the working
-directory. Git will not populate the contents of those files, which
+directory. Git will avoid populating the contents of those files, which
 makes a sparse checkout helpful when working in a repository with many
 files, but only a few are important to the current user.
 
@@ -117,10 +131,8 @@ directory, it updates the skip-worktree bits in the index based
 on this file. The files matching the patterns in the file will
 appear in the working directory, and the rest will not.
 
-To enable the sparse-checkout feature, run `git sparse-checkout init` to
-initialize a simple sparse-checkout file and enable the `core.sparseCheckout`
-config setting. Then, run `git sparse-checkout set` to modify the patterns in
-the sparse-checkout file.
+To enable the sparse-checkout feature, run `git sparse-checkout set` to
+set the patterns you want to use.
 
 To repopulate the working directory with all files, use the
 `git sparse-checkout disable` command.

add-patch.c

@@ -8,6 +8,7 @@
 #include "diff.h"
 #include "compat/terminal.h"
 #include "prompt.h"
+#include "refs.h"
 
 enum prompt_mode_type {
 	PROMPT_MODE_CHANGE = 0, PROMPT_DELETION, PROMPT_ADDITION, PROMPT_HUNK,
@@ -1695,35 +1696,36 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 		{ r }, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
 	};
 	size_t i, binary_count = 0;
+	struct object_id rev_oid, head_oid;
+	int rev_equals_head = 0;
 
 	init_add_i_state(&s.s, r);
 
 	if (mode == ADD_P_STASH)
 		s.mode = &patch_mode_stash;
 	else if (mode == ADD_P_RESET) {
-		/*
-		 * NEEDSWORK: Instead of comparing to the literal "HEAD",
-		 * compare the commit objects instead so that other ways of
-		 * saying the same thing (such as "@") are also handled
-		 * appropriately.
-		 *
-		 * This applies to the cases below too.
-		 */
-		if (!revision || !strcmp(revision, "HEAD"))
+		if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, &head_oid, NULL))
+			die("no such ref: HEAD");
+		if (revision) {
+			if (!resolve_ref_unsafe(revision, RESOLVE_REF_READING, &rev_oid, NULL))
+				die("no such ref: %s", revision);
+			rev_equals_head = strcmp(oid_to_hex(&rev_oid), oid_to_hex(&head_oid));
+		}
+		if (!revision || !rev_equals_head)
 			s.mode = &patch_mode_reset_head;
 		else
 			s.mode = &patch_mode_reset_nothead;
 	} else if (mode == ADD_P_CHECKOUT) {
 		if (!revision)
 			s.mode = &patch_mode_checkout_index;
-		else if (!strcmp(revision, "HEAD"))
+		else if (!rev_equals_head)
 			s.mode = &patch_mode_checkout_head;
 		else
 			s.mode = &patch_mode_checkout_nothead;
 	} else if (mode == ADD_P_WORKTREE) {
 		if (!revision)
 			s.mode = &patch_mode_checkout_index;
-		else if (!strcmp(revision, "HEAD"))
+		else if (!rev_equals_head)
 			s.mode = &patch_mode_worktree_head;
 		else
 			s.mode = &patch_mode_worktree_nothead;