git-pickaxe: blame rewritten.

Currently it does what git-blame does, but only faster.

More importantly, its internal structure is designed to support
content movement (aka cut-and-paste) more easily by allowing
more than one paths to be taken from the same commit.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Documentation/git-pickaxe.txt

+git-pickaxe(1)
+==============
+
+NAME
+----
+git-pickaxe - Show what revision and author last modified each line of a file
+
+SYNOPSIS
+--------
+'git-pickaxe' [-c] [-l] [-t] [-f] [-n] [-p] [-L n,m] [-S <revs-file>] [<rev>] [--] <file>
+
+DESCRIPTION
+-----------
+
+Annotates each line in the given file with information from the revision which
+last modified the line. Optionally, start annotating from the given revision.
+
+Also it can limit the range of lines annotated.
+
+This report doesn't tell you anything about lines which have been deleted or
+replaced; you need to use a tool such as gitlink:git-diff[1] or the "pickaxe"
+interface briefly mentioned in the following paragraph.
+
+Apart from supporting file annotation, git also supports searching the
+development history for when a code snippet occured in a change. This makes it
+possible to track when a code snippet was added to a file, moved or copied
+between files, and eventually deleted or replaced. It works by searching for
+a text string in the diff. A small example:
+
+-----------------------------------------------------------------------------
+$ git log --pretty=oneline -S'blame_usage'
+5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file>
+ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
+-----------------------------------------------------------------------------
+
+OPTIONS
+-------
+-c, --compatibility::
+	Use the same output mode as gitlink:git-annotate[1] (Default: off).
+
+-L n,m::
+	Annotate only the specified line range (lines count from 1).
+
+-l, --long::
+	Show long rev (Default: off).
+
+-t, --time::
+	Show raw timestamp (Default: off).
+
+-S, --rev-file <revs-file>::
+	Use revs from revs-file instead of calling gitlink:git-rev-list[1].
+
+-f, --show-name::
+	Show filename in the original commit.  By default
+	filename is shown if there is any line that came from a
+	file with different name, due to rename detection.
+
+-n, --show-number::
+	Show line number in the original commit (Default: off).
+
+-p, --porcelain::
+	Show in a format designed for machine consumption.
+
+-h, --help::
+	Show help message.
+
+
+THE PORCELAIN FORMAT
+--------------------
+
+In this format, each line is output after a header; the
+header at the minumum has the first line which has:
+
+- 40-byte SHA-1 of the commit the line is attributed to;
+- the line number of the line in the original file;
+- the line number of the line in the final file;
+- on a line that starts a group of line from a different
+  commit than the previous one, the number of lines in this
+  group.  On subsequent lines this field is absent.
+
+This header line is followed by the following information
+at least once for each commit:
+
+- author name ("author"), email ("author-mail"), time
+  ("author-time"), and timezone ("author-tz"); similarly
+  for committer.
+- filename in the commit the line is attributed to.
+- the first line of the commit log message ("summary").
+
+The contents of the actual line is output after the above
+header, prefixed by a TAB. This is to allow adding more
+header elements later.
+
+SEE ALSO
+--------
+gitlink:git-blame[1]
+
+AUTHOR
+------
+Written by Junio C Hamano <junkio@cox.net>
+
+GIT
+---
+Part of the gitlink:git[7] suite

Documentation/git.txt

@@ -430,6 +430,9 @@ gitlink:git-annotate[1]::
 gitlink:git-blame[1]::
 	Blame file lines on commits.
 
+gitlink:git-pickaxe[1]::
+	Find out where each line in a file came from.
+
 gitlink:git-check-ref-format[1]::
 	Make sure ref name is well formed.
 

Makefile

@@ -288,6 +288,7 @@ BUILTIN_OBJS = \
 	builtin-mv.o \
 	builtin-name-rev.o \
 	builtin-pack-objects.o \
+	builtin-pickaxe.o \
 	builtin-prune.o \
 	builtin-prune-packed.o \
 	builtin-push.o \

builtin.h

@@ -39,6 +39,7 @@ extern int cmd_mailsplit(int argc, const char **argv, const char *prefix);
 extern int cmd_mv(int argc, const char **argv, const char *prefix);
 extern int cmd_name_rev(int argc, const char **argv, const char *prefix);
 extern int cmd_pack_objects(int argc, const char **argv, const char *prefix);
+extern int cmd_pickaxe(int argc, const char **argv, const char *prefix);
 extern int cmd_prune(int argc, const char **argv, const char *prefix);
 extern int cmd_prune_packed(int argc, const char **argv, const char *prefix);
 extern int cmd_push(int argc, const char **argv, const char *prefix);

git.c

@@ -245,6 +245,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "mv", cmd_mv, RUN_SETUP },
 		{ "name-rev", cmd_name_rev, RUN_SETUP },
 		{ "pack-objects", cmd_pack_objects, RUN_SETUP },
+		{ "pickaxe", cmd_pickaxe, RUN_SETUP },
 		{ "prune", cmd_prune, RUN_SETUP },
 		{ "prune-packed", cmd_prune_packed, RUN_SETUP },
 		{ "push", cmd_push, RUN_SETUP },

t/annotate-tests.sh

@@ -4,6 +4,7 @@
 check_count () {
 	head=
 	case "$1" in -h) head="$2"; shift; shift ;; esac
+	echo "$PROG file $head" >&4
 	$PROG file $head >.result || return 1
 	cat .result | perl -e '
 		my %expect = (@ARGV);

t/t8003-pickaxe.sh

+#!/bin/sh
+
+test_description='git-pickaxe'
+. ./test-lib.sh
+
+PROG='git pickaxe -c'
+. ../annotate-tests.sh
+
+test_done