[PATCH stable] glog: fix crash on empty revision range

[Eric Eisner]

# HG changeset patch
# User Eric Eisner <ede at mit.edu>
# Date 1277440552 25200
# Branch stable
# Node ID a883030d864a26873629eb5b1457717d1c909a57
# Parent  9fa255c324065b673caf3ef6374eb8da8cb42341
glog: fix crash on empty revision range

diff --git a/hgext/graphlog.py b/hgext/graphlog.py
--- a/hgext/graphlog.py
+++ b/hgext/graphlog.py
@@ -209,6 +209,8 @@ def ascii(ui, state, type, char, text, c
 def get_revs(repo, rev_opt):
     if rev_opt:
         revs = revrange(repo, rev_opt)
+        if len(revs) == 0:
+            return (nullrev, nullrev)
         return (max(revs), min(revs))
     else:
         return (len(repo) - 1, 0)
diff --git a/tests/test-glog b/tests/test-glog
--- a/tests/test-glog
+++ b/tests/test-glog
@@ -146,6 +146,9 @@ hg glog a
 echo % unused arguments
 hg glog -q foo bar || echo failed
 
+echo % empty revision range - display nothing
+hg glog -r 1..0
+
 echo % from outer space
 cd ..
 hg glog -l1 repo
diff --git a/tests/test-glog.out b/tests/test-glog.out
--- a/tests/test-glog.out
+++ b/tests/test-glog.out
@@ -548,6 +548,7 @@ hg glog [OPTION]... [FILE]
 
 show revision history alongside an ASCII revision graph
 failed
+% empty revision range - display nothing
 % from outer space
 @  changeset:   34:fea3ac5810e0
 |  tag:         tip