Illegal size param in the bid request for the interstitial ad units

[YuriyVelichkoOpenX]

Motivation

One of the demand partners complains about ad requests with unsupported ad sizes: 360x728, 320x637, 392x776, etc.

The reason is that prebid SDK sends the device size in imp.banner.format[0].

If the publisher sets the size in the stored impression it will be overridden with the size from the bid request. It means that imp.banner.format[0] will never be changed and will always reflect the device size.

According to the PBS logic, if the publisher sets the size like 1x1 the server will place the device size into the final bid request.

https://github.com/prebid/prebid-server/blob/d384e91bf99f886927a2bd412fd439502a1de088/endpoints/openrtb2/interstitial.go#L41

Workaround

There is a workaround here. If the publisher set the minWidthPerc and minHeightPrec the PBS will generate a range of acceptable sizes and put it into the bid request. In a result, the demand partner will receive several sizes in the imp.banner.format.

Objective

There is only one requirement here to fix the wrong logic:

• do not send device size in the imp.banner.format[0] for interstitial ads.

[jsligh]

@YuriyVelichkoPI is this still relevant?

[YuriyVelichkoPI]

@ValentinPostindustria @OlenaPostindustria , please check if this behavior is still actual. If I remember correctly, we made some changes to interstitial bid requests.