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This patch fixes several issues related to the min/max aggregate functions and their handling of 'nan' and 'inf': - Previously, if 'inf' or '-inf' was the only value for the min/max and codegen was being used, the result would be incorrect. This occurred, for example in the case of 'inf' and 'min', because we set an initial value of numeric_limits::max, which is less than 'inf', so the returned min was numeric_limits::max when it should be 'inf'. The fix is to set the initial value to numeric_limits::infinity. - Previously, if one of the values was 'nan', the result of min/max was non-deterministic depending on the order the values were evaluated in. This occurs because 'nan' < or > 'any value' is always false, so if the first value added was 'nan', all other comparisons would be false and 'nan' would be returned, whereas if the first value wasn't 'nan' then the 'nan' wouldn't be returned. The fix is to treat 'nan' specially and to always return 'nan' if there is a single 'nan' value. Testing: - Added e2e tests for both scenarios, as well as adding a little extra nan/inf coverage for other aggregate functions. Change-Id: Ia1e206105937ce5afc75ca5044597d39b3dc6a81 Reviewed-on: http://gerrit.cloudera.org:8080/8854 Reviewed-by: Bikramjeet Vig <bikramjeet.vig@cloudera.com> Reviewed-by: Tim Armstrong <tarmstrong@cloudera.com> Tested-by: Impala Public Jenkins