doc: add more pointers to gitattributes(5) for userdiff

Several Git commands can make use of the builtin userdiff patterns, but
it's not obvious in the documentation. Add pointers to the 'Defining a
custom hunk header' part of gitattributes(5) in the description of the
following options:

- the '--function-context' option of `git diff` and friends
- the '--function-context' option of `git grep`
- the '-L :<funcname>' option of `git log`, `gitk` and `git blame`

In 'git-grep.txt', take the opportunity to use backticks in the
description of '--show-function', and improve the wording of the
desription of '--function-context'.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/Documentation/line-range-format.txt b/Documentation/line-range-format.txt
index 43759ee..9b51e9f 100644
--- a/Documentation/line-range-format.txt
+++ b/Documentation/line-range-format.txt
@@ -27,4 +27,6 @@ regular expression that denotes the range from the first funcname line
 that matches '<funcname>', up to the next funcname line. `:<funcname>`
 searches from the end of the previous `-L` range, if any, otherwise
 from the start of file. `^:<funcname>` searches from the start of
-file.
+file. The function names are determined in the same way as `git diff`
+works out patch hunk headers (see 'Defining a custom hunk-header'
+in linkgit:gitattributes[5]).