Problem

A .version file containing this:

    "KSP_VERSION":
    {
        "MAJOR":1,
        "MINOR":5,
        "PATCH":0
    },
     "KSP_VERSION_MIN":{
         "MAJOR":1,
         "MINOR":5,
         "PATCH":0
     },

Is resulting in this metadata:

    "ksp_version": "1.5.0",

The minimum value is essentially ignored.

Cause

The KSP-AVC spec says:

• KSP_VERSION - Optional, Required for MIN/MAX
  Version of KSP that the add-on was made to support.
• KSP_VERSION_MIN - Optional
  Minimum version of KSP that the add-on supports.
  Requires KSP_VERSION field to work.
• KSP_VERSION_MAX - Optional
  Maximum version of KSP that the add-on supports.
  Requires KSP_VERSION field to work.

This implies that if you want to specify KSP_VERSION_MIN, you must specify KSP_VERSION. This does not make sense, but it's in the spec, and some modders may feel compelled to follow it strictly as written.

Under that interpretation, if you wanted to specify "all versions after 1.5.0", you would create a file as shown above, but it would not translate into equivalent CKAN metadata. This is because the KSP_VERSION value is used as a fallback for both the min and the max if either are absent:

Changes

Now if a .version file has KSP_VERSION_MIN and KSP_VERSION but not KSP_VERSION_MAX, we don't set ksp_version_max. (And vice versa for MAX and MIN.)