[PATCH v3 13/13] some document update

[Bo Yang <struggleyb.nku@gmail.com>]

Signed-off-by: Bo Yang <struggleyb.nku@gmail.com>
---
 Documentation/git-log.txt |   30 ++++++++++++++++++++++++++++++
 1 files changed, 30 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 0e6ff31..14a9703 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -9,6 +9,7 @@ git-log - Show commit logs
 SYNOPSIS
 --------
 'git log' [<options>] [<since>..<until>] [[\--] <path>...]
+'git log' [<options>] -L n,m <path>
 
 DESCRIPTION
 -----------
@@ -19,6 +20,9 @@ command to control what is shown and how, and options applicable to
 the 'git diff-*' commands to control how the changes
 each commit introduces are shown.
 
+With '-L' option, the command will help to trace the history of user specified
+line ranges. It can trace multiple ranges coming from multiple files.
+
 
 OPTIONS
 -------
@@ -72,6 +76,32 @@ include::diff-options.txt[]
 	to be prefixed with "\-- " to separate them from options or
 	refnames.
 
+-L <start>,<end>::
+	The line range.  <start> and <end> can take one of these forms:
+
+- number
++
+If <start> or <end> is a number, it specifies an
+absolute line number (lines count from 1).
++
+
+- /regex/
++
+This form will use the first line matching the given
+POSIX regex.  If <end> is a regex, it will search
+starting at the line given by <start>.
++
+
+- +offset or -offset
++
+This is only valid for <end> and will specify a number
+of lines before or after the line given by <start>.
++
+
+--always-print::
+	Always print the interesting range even if the current commit
+	does not change any line of the range.
+
 
 include::rev-list-options.txt[]
 
-- 
1.7.0.2.273.gc2413.dirty