# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1475327938 -3600
# Node ID 3e3f2201bbdfada996cf9c7d29c7bf86587c09f3
# Parent  ff7697b436aba70b752a6277eaf4e9ef298e3640
annotate: calculate line count correctly

Before this patch, the "lines" function inside "annotate" returns 1 for
empty text (''). This patch makes it 0. Because the function should match
mdiff.splitnewlines (used by mdiff.allblocks), or s.splitlines (used at the
end of the "annotate" method). Both len(mdiff.splitnewlines('')) and
len(''.splitlines(True)) are 0.

This issue was discovered while testing fastannotate [1].

I could not find a test case to reveal this issue. However in theory this
could reduce memory usage a little bit, and avoids surprises when people
are touching this area in the future.

[1]: https://bitbucket.org/facebook/hg-experimental/commits/525b3b98e93a

diff -r ff7697b436ab -r 3e3f2201bbdf mercurial/context.py
--- a/mercurial/context.py	Sun Oct 02 05:29:17 2016 +0530
+++ b/mercurial/context.py	Sat Oct 01 14:18:58 2016 +0100
@@ -930,7 +930,7 @@
         def lines(text):
             if text.endswith("\n"):
                 return text.count("\n")
-            return text.count("\n") + 1
+            return text.count("\n") + int(bool(text))
 
         if linenumber:
             def decorate(text, rev):