[PATCH] doc: make clear --assume-unchanged's user contract

[Philip Oakley <philipoakley@iee.org>]

Many users misunderstand the --assume-unchanged contract, believing
it means Git won't look at the flagged file.

Be explicit that the --assume-unchanged contract is by the user that
they will NOT change the file so that Git does not need to look (and
expend, fore example, lstat(2) cycles)

Signed-off-by: Philip Oakley <philipoakley@iee.org>
---
 Documentation/git-update-index.txt | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-update-index.txt b/Documentation/git-update-index.txt
index 929869b..c045509 100644
--- a/Documentation/git-update-index.txt
+++ b/Documentation/git-update-index.txt
@@ -82,13 +82,14 @@ OPTIONS
         Set the execute permissions on the updated files.
 
 --[no-]assume-unchanged::
-	When these flags are specified, the object names recorded
+	When this flag is specified, the object names recorded
 	for the paths are not updated.  Instead, these options
 	set and unset the "assume unchanged" bit for the
-	paths.  When the "assume unchanged" bit is on, Git stops
+	paths.  When the "assume unchanged" bit is on, the user promise
+	is not to change the file, so Git stops
 	checking the working tree files for possible
-	modifications, so you need to manually unset the bit to
-	tell Git when you change the working tree file. This is
+	modifications, so when you change the working tree file you
+	need to manually unset the bit to tell Git . This is
 	sometimes helpful when working with a big project on a
 	filesystem that has very slow lstat(2) system call
 	(e.g. cifs).
-- 
1.9.4.msysgit.0