To: J3                                                     J3/20-103r1
From: John Reid & Bill Long
Subject: FORM TEAM and invalid NEW_INDEX= values
Date: 2020-February-24
Reference: 18-007r1, 19-181, 19-242


1. Introduction

This paper clarifies an issue that arose regarding the operation of
FORM TEAM statements. It replaces 19-242 and part of 19-181 that
address the same issue.

2. Question

What happens if it was intended for the execution of a FORM TEAM
statement with a NEW_INDEX specifier to form a new team with 16 images
but one of the 16 images is found to have failed?

3. Response

If none of the other 15 images fails before completing execution of
the FORM TEAM statement, the FORM TEAM statement has a STAT=
specifier, and none of the images specifies 16 as its NEW_INDEX value,
the new team will consist of these 15 images; the STAT= specifier will
return the value STAT_FAILED_IMAGE. The standard (11.6.9, para 3)
requires of each NEW_INDEX= value that "It shall be ... less than or
equal to the number of images in the team". The program would not
satisfy this requirement if an active image specified 16 as its
NEW_INDEX value because the new team would consist of at most 15
images; in this case the standard specifies no semantics for the
program. If a STAT= specifier is present, an implementation might
return a nonzero value for the STAT= variable that is different from
STAT_FAILED_IMAGE or STAT_STOPPED_IMAGE that indicated that an invalid
image index was specified. But this is not required by the standard.

4. Edits

None.