[COMMITTERS] pgsql: Fix base backup rate limiting in presence of slow i/o

Fix base backup rate limiting in presence of slow i/o

When source i/o on disk was too slow compared to the rate limiting
specified, the system could end up with a negative value for sleep that
it never got out of, which caused rate limiting to effectively be
turned off.

Discussion: https://postgr.es/m/CABUevEy_-e0YvL4ayoX8bH_Ja9w%2BBHoP6jUgdxZuG2nEj3uAfQ%40mail.gmail.com

Analysis by me, patch by Antonin Houska

Branch
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REL9_6_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/1c8ad594e5cb46952bd70f8a0f2f8681912dc223

Modified Files
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src/backend/replication/basebackup.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)