Merge branch 'rh/ishes-doc'

We liberally use "committish" and "commit-ish" (and "treeish" and
"tree-ish"); as these are non-words, let's unify these terms to
their dashed form.  More importantly, clarify the documentation on
object peeling using these terms.

* rh/ishes-doc:
  glossary: fix and clarify the definition of 'ref'
  revisions.txt: fix and clarify <rev>^{<type>}
  glossary: more precise definition of tree-ish (a.k.a. treeish)
  use 'commit-ish' instead of 'committish'
  use 'tree-ish' instead of 'treeish'
  glossary: define commit-ish (a.k.a. committish)
  glossary: mention 'treeish' as an alternative to 'tree-ish'

Author: gitster

Documentation/RelNotes/1.7.11.2.txt

@@ -31,7 +31,7 @@ Fixes since v1.7.11.1
  * "git diff --no-index" did not work with pagers correctly.
 
  * "git diff COPYING HEAD:COPYING" gave a nonsense error message that
-   claimed that the treeish HEAD did not have COPYING in it.
+   claimed that the tree-ish HEAD did not have COPYING in it.
 
  * When "git log" gets "--simplify-merges/by-decoration" together with
    "--first-parent", the combination of these options makes the

Documentation/config.txt

@@ -170,8 +170,8 @@ advice.*::
 	pushNeedsForce::
 		Shown when linkgit:git-push[1] rejects an update that
 		tries to overwrite a remote ref that points at an
-		object that is not a committish, or make the remote
-		ref point at an object that is not a committish.
+		object that is not a commit-ish, or make the remote
+		ref point at an object that is not a commit-ish.
 	statusHints::
 		Show directions on how to proceed from the current
 		state in the output of linkgit:git-status[1], in

Documentation/git-cat-file.txt

@@ -54,7 +54,7 @@ OPTIONS
 
 --textconv::
 	Show the content as transformed by a textconv filter. In this case,
-	<object> has be of the form <treeish>:<path>, or :<path> in order
+	<object> has be of the form <tree-ish>:<path>, or :<path> in order
 	to apply the filter to the content recorded in the index at <path>.
 
 --batch::

Documentation/git-describe.txt

@@ -9,7 +9,7 @@ git-describe - Show the most recent tag that is reachable from a commit
 SYNOPSIS
 --------
 [verse]
-'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
+'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] <commit-ish>...
 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
 
 DESCRIPTION
@@ -26,8 +26,8 @@ see the -a and -s options to linkgit:git-tag[1].
 
 OPTIONS
 -------
-<committish>...::
-	Committish object names to describe.
+<commit-ish>...::
+	Commit-ish object names to describe.
 
 --dirty[=<mark>]::
 	Describe the working tree.
@@ -57,7 +57,7 @@ OPTIONS
 
 --candidates=<n>::
 	Instead of considering only the 10 most recent tags as
-	candidates to describe the input committish consider
+	candidates to describe the input commit-ish consider
 	up to <n> candidates.  Increasing <n> above 10 will take
 	slightly longer but may produce a more accurate result.
 	An <n> of 0 will cause only exact matches to be output.
@@ -145,7 +145,7 @@ be sufficient to disambiguate these commits.
 SEARCH STRATEGY
 ---------------
 
-For each committish supplied, 'git describe' will first look for
+For each commit-ish supplied, 'git describe' will first look for
 a tag which tags exactly that commit.  Annotated tags will always
 be preferred over lightweight tags, and tags with newer dates will
 always be preferred over tags with older dates.  If an exact match
@@ -154,12 +154,12 @@ is found, its name will be output and searching will stop.
 If an exact match was not found, 'git describe' will walk back
 through the commit history to locate an ancestor commit which
 has been tagged.  The ancestor's tag will be output along with an
-abbreviation of the input committish's SHA-1. If '--first-parent' was
+abbreviation of the input commit-ish's SHA-1. If '--first-parent' was
 specified then the walk will only consider the first parent of each
 commit.
 
 If multiple tags were found during the walk then the tag which
-has the fewest commits different from the input committish will be
+has the fewest commits different from the input commit-ish will be
 selected and output.  Here fewest commits different is defined as
 the number of commits which would be shown by `git log tag..input`
 will be the smallest number of commits possible.

Documentation/git-fast-import.txt

@@ -380,8 +380,8 @@ change to the project.
 	('author' (SP <name>)? SP LT <email> GT SP <when> LF)?
 	'committer' (SP <name>)? SP LT <email> GT SP <when> LF
 	data
-	('from' SP <committish> LF)?
-	('merge' SP <committish> LF)?
+	('from' SP <commit-ish> LF)?
+	('merge' SP <commit-ish> LF)?
 	(filemodify | filedelete | filecopy | filerename | filedeleteall | notemodify)*
 	LF?
 ....
@@ -460,9 +460,9 @@ as the current commit on that branch is automatically assumed to
 be the first ancestor of the new commit.
 
 As `LF` is not valid in a Git refname or SHA-1 expression, no
-quoting or escaping syntax is supported within `<committish>`.
+quoting or escaping syntax is supported within `<commit-ish>`.
 
-Here `<committish>` is any of the following:
+Here `<commit-ish>` is any of the following:
 
 * The name of an existing branch already in fast-import's internal branch
   table.  If fast-import doesn't know the name, it's treated as a SHA-1
@@ -509,7 +509,7 @@ additional ancestors (forming a 16-way merge).  For this reason
 it is suggested that frontends do not use more than 15 `merge`
 commands per commit; 16, if starting a new, empty branch.
 
-Here `<committish>` is any of the commit specification expressions
+Here `<commit-ish>` is any of the commit specification expressions
 also accepted by `from` (see above).
 
 `filemodify`
@@ -677,8 +677,8 @@ paths for a commit are encouraged to do so.
 `notemodify`
 ^^^^^^^^^^^^
 Included in a `commit` `<notes_ref>` command to add a new note
-annotating a `<committish>` or change this annotation contents.
-Internally it is similar to filemodify 100644 on `<committish>`
+annotating a `<commit-ish>` or change this annotation contents.
+Internally it is similar to filemodify 100644 on `<commit-ish>`
 path (maybe split into subdirectories). It's not advised to
 use any other commands to write to the `<notes_ref>` tree except
 `filedeleteall` to delete all existing notes in this tree.
@@ -691,7 +691,7 @@ External data format::
 	commit that is to be annotated.
 +
 ....
-	'N' SP <dataref> SP <committish> LF
+	'N' SP <dataref> SP <commit-ish> LF
 ....
 +
 Here `<dataref>` can be either a mark reference (`:<idnum>`)
@@ -704,13 +704,13 @@ Inline data format::
 	command.
 +
 ....
-	'N' SP 'inline' SP <committish> LF
+	'N' SP 'inline' SP <commit-ish> LF
 	data
 ....
 +
 See below for a detailed description of the `data` command.
 
-In both formats `<committish>` is any of the commit specification
+In both formats `<commit-ish>` is any of the commit specification
 expressions also accepted by `from` (see above).
 
 `mark`
@@ -741,7 +741,7 @@ lightweight (non-annotated) tags see the `reset` command below.
 
 ....
 	'tag' SP <name> LF
-	'from' SP <committish> LF
+	'from' SP <commit-ish> LF
 	'tagger' (SP <name>)? SP LT <email> GT SP <when> LF
 	data
 ....
@@ -786,11 +786,11 @@ branch from an existing commit without creating a new commit.
 
 ....
 	'reset' SP <ref> LF
-	('from' SP <committish> LF)?
+	('from' SP <commit-ish> LF)?
 	LF?
 ....
 
-For a detailed description of `<ref>` and `<committish>` see above
+For a detailed description of `<ref>` and `<commit-ish>` see above
 under `commit` and `from`.
 
 The `LF` after the command is optional (it used to be required).

Documentation/git-merge-tree.txt

@@ -13,7 +13,7 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Reads three treeish, and output trivial merge results and
+Reads three tree-ish, and output trivial merge results and
 conflicting stages to the standard output.  This is similar to
 what three-way 'git read-tree -m' does, but instead of storing the
 results in the index, the command outputs the entries to the

Documentation/git-name-rev.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git name-rev' [--tags] [--refs=<pattern>]
-	       ( --all | --stdin | <committish>... )
+	       ( --all | --stdin | <commit-ish>... )
 
 DESCRIPTION
 -----------

Documentation/git-push.txt

@@ -121,7 +121,7 @@ already exists on the remote side.
 --follow-tags::
 	Push all the refs that would be pushed without this option,
 	and also push annotated tags in `refs/tags` that are missing
-	from the remote but are pointing at committish that are
+	from the remote but are pointing at commit-ish that are
 	reachable from the refs being pushed.
 
 --receive-pack=<git-receive-pack>::

Documentation/gitcli.txt

@@ -106,7 +106,7 @@ couple of magic command line options:
 +
 ---------------------------------------------
 $ git describe -h
-usage: git describe [options] <committish>*
+usage: git describe [options] <commit-ish>*
    or: git describe [options] --dirty
 
     --contains            find the tag that comes after the commit

Documentation/glossary-content.txt

@@ -82,6 +82,18 @@ to point at the new commit.
 	to the top <<def_directory,directory>> of the stored
 	revision.
 
+[[def_commit-ish]]commit-ish (also committish)::
+	A <<def_commit_object,commit object>> or an
+	<<def_object,object>> that can be recursively dereferenced to
+	a commit object.
+	The following are all commit-ishes:
+	a commit object,
+	a <<def_tag_object,tag object>> that points to a commit
+	object,
+	a tag object that points to a tag object that points to a
+	commit object,
+	etc.
+
 [[def_core_git]]core Git::
 	Fundamental data structures and utilities of Git. Exposes only limited
 	source code management tools.
@@ -427,10 +439,20 @@ should not be combined with other pathspec.
 	to the result.
 
 [[def_ref]]ref::
-	A 40-byte hex representation of a <<def_SHA1,SHA-1>> or a name that
-	denotes a particular <<def_object,object>>. They may be stored in
-	a file under `$GIT_DIR/refs/` directory, or
-	in the `$GIT_DIR/packed-refs` file.
+	A name that begins with `refs/` (e.g. `refs/heads/master`)
+	that points to an <<def_object_name,object name>> or another
+	ref (the latter is called a <<def_symref,symbolic ref>>).
+	For convenience, a ref can sometimes be abbreviated when used
+	as an argument to a Git command; see linkgit:gitrevisions[7]
+	for details.
+	Refs are stored in the <<def_repository,repository>>.
++
+The ref namespace is hierarchical.
+Different subhierarchies are used for different purposes (e.g. the
+`refs/heads/` hierarchy is used to represent local branches).
++
+There are a few special-purpose refs that do not begin with `refs/`.
+The most notable example is `HEAD`.
 
 [[def_reflog]]reflog::
 	A reflog shows the local "history" of a ref.  In other words,
@@ -530,10 +552,19 @@ should not be combined with other pathspec.
 	with refs to the associated blob and/or tree objects. A
 	<<def_tree,tree>> is equivalent to a <<def_directory,directory>>.
 
-[[def_tree-ish]]tree-ish::
-	A <<def_ref,ref>> pointing to either a <<def_commit_object,commit
-	object>>, a <<def_tree_object,tree object>>, or a <<def_tag_object,tag
-	object>> pointing to a tag or commit or tree object.
+[[def_tree-ish]]tree-ish (also treeish)::
+	A <<def_tree_object,tree object>> or an <<def_object,object>>
+	that can be recursively dereferenced to a tree object.
+	Dereferencing a <<def_commit_object,commit object>> yields the
+	tree object corresponding to the <<def_revision,revision>>'s
+	top <<def_directory,directory>>.
+	The following are all tree-ishes:
+	a <<def_commit-ish,commit-ish>>,
+	a tree object,
+	a <<def_tag_object,tag object>> that points to a tree object,
+	a tag object that points to a tag object that points to a tree
+	object,
+	etc.
 
 [[def_unmerged_index]]unmerged index::
 	An <<def_index,index>> which contains unmerged