Merge branch 'tl/ls-tree-oid-only'

"git ls-tree" learns "--oid-only" option, similar to "--name-only",
and more generalized "--format" option.

* tl/ls-tree-oid-only:
  ls-tree: split up "fast path" callbacks
  ls-tree: detect and error on --name-only --name-status
  ls-tree: support --object-only option for "git-ls-tree"
  ls-tree: introduce "--format" option
  cocci: allow padding with `strbuf_addf()`
  ls-tree: introduce struct "show_tree_data"
  ls-tree: slightly refactor `show_tree()`
  ls-tree: fix "--name-only" and "--long" combined use bug
  ls-tree: simplify nesting if/else logic in "show_tree()"
  ls-tree: rename "retval" to "recurse" in "show_tree()"
  ls-tree: use "size_t", not "int" for "struct strbuf"'s "len"
  ls-tree: use "enum object_type", not {blob,tree,commit}_type
  ls-tree: add missing braces to "else" arms
  ls-tree: remove commented-out code
  ls-tree tests: add tests for --name-status

Author: gitster

Documentation/git-ls-tree.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git ls-tree' [-d] [-r] [-t] [-l] [-z]
-	    [--name-only] [--name-status] [--full-name] [--full-tree] [--abbrev[=<n>]]
+	    [--name-only] [--name-status] [--object-only] [--full-name] [--full-tree] [--abbrev[=<n>]] [--format=<format>]
 	    <tree-ish> [<path>...]
 
 DESCRIPTION
@@ -59,6 +59,15 @@ OPTIONS
 --name-only::
 --name-status::
 	List only filenames (instead of the "long" output), one per line.
+	Cannot be combined with `--object-only`.
+
+--object-only::
+	List only names of the objects, one per line. Cannot be combined
+	with `--name-only` or `--name-status`.
+	This is equivalent to specifying `--format='%(objectname)'`, but
+	for both this option and that exact format the command takes a
+	hand-optimized codepath instead of going through the generic
+	formatting mechanism.
 
 --abbrev[=<n>]::
 	Instead of showing the full 40-byte hexadecimal object
@@ -74,6 +83,16 @@ OPTIONS
 	Do not limit the listing to the current working directory.
 	Implies --full-name.
 
+--format=<format>::
+	A string that interpolates `%(fieldname)` from the result
+	being shown. It also interpolates `%%` to `%`, and
+	`%xx` where `xx` are hex digits interpolates to character
+	with hex code `xx`; for example `%00` interpolates to
+	`\0` (NUL), `%09` to `\t` (TAB) and `%0a` to `\n` (LF).
+	When specified, `--format` cannot be combined with other
+	format-altering options, including `--long`, `--name-only`
+	and `--object-only`.
+
 [<path>...]::
 	When paths are given, show them (note that this isn't really raw
 	pathnames, but rather a list of patterns to match).  Otherwise
@@ -82,16 +101,29 @@ OPTIONS
 
 Output Format
 -------------
-        <mode> SP <type> SP <object> TAB <file>
+
+The output format of `ls-tree` is determined by either the `--format`
+option, or other format-altering options such as `--name-only` etc.
+(see `--format` above).
+
+The use of certain `--format` directives is equivalent to using those
+options, but invoking the full formatting machinery can be slower than
+using an appropriate formatting option.
+
+In cases where the `--format` would exactly map to an existing option
+`ls-tree` will use the appropriate faster path. Thus the default format
+is equivalent to:
+
+	%(objectmode) %(objecttype) %(objectname)%x09%(path)
 
 This output format is compatible with what `--index-info --stdin` of
 'git update-index' expects.
 
 When the `-l` option is used, format changes to
 
-        <mode> SP <type> SP <object> SP <object size> TAB <file>
+	%(objectmode) %(objecttype) %(objectname) %(objectsize:padded)%x09%(path)
 
-Object size identified by <object> is given in bytes, and right-justified
+Object size identified by <objectname> is given in bytes, and right-justified
 with minimum width of 7 characters.  Object size is given only for blobs
 (file) entries; for other entries `-` character is used in place of size.
 
@@ -100,6 +132,34 @@ quoted as explained for the configuration variable `core.quotePath`
 (see linkgit:git-config[1]).  Using `-z` the filename is output
 verbatim and the line is terminated by a NUL byte.
 
+Customized format:
+
+It is possible to print in a custom format by using the `--format` option,
+which is able to interpolate different fields using a `%(fieldname)` notation.
+For example, if you only care about the "objectname" and "path" fields, you
+can execute with a specific "--format" like
+
+	git ls-tree --format='%(objectname) %(path)' <tree-ish>
+
+FIELD NAMES
+-----------
+
+Various values from structured fields can be used to interpolate
+into the resulting output. For each outputing line, the following
+names can be used:
+
+objectmode::
+	The mode of the object.
+objecttype::
+	The type of the object (`blob` or `tree`).
+objectname::
+	The name of the object.
+objectsize[:padded]::
+	The size of the object ("-" if it's a tree).
+	It also supports a padded format of size with "%(size:padded)".
+path::
+	The pathname of the object.
+
 GIT
 ---
 Part of the linkgit:git[1] suite