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Testing Debian version number comparisons

The Debian Policy Manual specifies how Debian version numbers are interpreted. The specification is reasonably straightforward on the surface, but there are a lot of details that need to be exactly right. The canonical implementation of this comparision is dpkg --compare-versions, but it has been implemented in other places as well, for various reasons.

It strikes me that it would be cool to have a set of test cases that could be used to verify that all implementations of version number comparisons work the same way. I envision a file like this:

1 eq 1
1 lt 2
10 gt 2
1.1 lt 2
1 gt 0
1 eq 0:1
2 lt 1:0
1 lt 1-0

(For simplicity, let's assume the only relations are eq, lt, and gt.) An implementation of the version number comparison algorithm could use such a data set in its test suite.

A quick and dirty implementation for dpkg might look like this:

#!/bin/sh

set -e

error=0
grep -vE '^:space:*(#.*)?$' "$@" |
while read v1 relation v2
do
    if ! dpkg --compare-versions "$v1" "$relation" "$v2"
    then
        echo "Error: $v1 $relation $v2" 1>&2
        error=1
    fi
done
exit "$error"

I don't have time to think through all cases and construct a comprehensive set of test cases, but I think someone should do that.