This appears to be Debian bug #759099 [1] fixed in apt 1.0.7 which should not be occurring in Ubuntu Vivid which provides apt 1.0.9.3ubuntu1. I can not reproduce this problem on any of my local Ubuntu Vivid installations.
Is it possible you have a locally-installed version of the apt package that does not contain the fix for#759099?
This appears to be Debian bug #759099 [1] fixed in apt 1.0.7 which should not be occurring in Ubuntu Vivid which provides apt 1.0.9.3ubuntu1. I can not reproduce this problem on any of my local Ubuntu Vivid installations.
Is it possible you have a locally-installed version of the apt package that does not contain the fix for#759099?
[1] ttps:// bugs.debian. org/cgi- bin/bugreport. cgi?bug=759099