From 69dc5ae408f68c302029a6b43912a2cc16b1256c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 5 Aug 2016 18:58:12 -0400 Subject: [PATCH] Teach libpq to decode server version correctly from future servers. Beginning with the next development cycle, PG servers will report two-part not three-part version numbers. Fix libpq so that it will compute the correct numeric representation of such server versions for reporting by PQserverVersion(). It's desirable to get this into the field and back-patched ASAP, so that older clients are more likely to understand the new server version numbering by the time any such servers are in the wild. (The results with an old client would probably not be catastrophic anyway for a released server; for example "10.1" would be interpreted as 100100 which would be wrong in detail but would not likely cause an old client to misbehave badly. But "10devel" or "10beta1" would result in sversion==0 which at best would result in disabling all use of modern features.) Extracted from a patch by Peter Eisentraut; comments added by me Patch: <802ec140-635d-ad86-5fdf-d3af0e260c22@2ndquadrant.com> --- src/interfaces/libpq/fe-exec.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c index 2621767fd4..d1b91c841c 100644 --- a/src/interfaces/libpq/fe-exec.c +++ b/src/interfaces/libpq/fe-exec.c @@ -983,14 +983,31 @@ pqSaveParameterStatus(PGconn *conn, const char *name, const char *value) cnt = sscanf(value, "%d.%d.%d", &vmaj, &vmin, &vrev); - if (cnt < 2) - conn->sversion = 0; /* unknown */ - else + if (cnt == 3) { - if (cnt == 2) - vrev = 0; + /* old style, e.g. 9.6.1 */ conn->sversion = (100 * vmaj + vmin) * 100 + vrev; } + else if (cnt == 2) + { + if (vmaj >= 10) + { + /* new style, e.g. 10.1 */ + conn->sversion = 100 * 100 * vmaj + vmin; + } + else + { + /* old style without minor version, e.g. 9.6devel */ + conn->sversion = (100 * vmaj + vmin) * 100; + } + } + else if (cnt == 1) + { + /* new style without minor version, e.g. 10devel */ + conn->sversion = 100 * 100 * vmaj; + } + else + conn->sversion = 0; /* unknown */ } }