Avoid unportable strftime() behavior in pg_dump/pg_dumpall.

Commit ad5d46a4494b0b480a3af246bb4227d9bdadca37 thought that we could
get around the known portability issues of strftime's %Z specifier by
using %z instead.  However, that idea seems to have been innocent of
any actual research, as it certainly missed the facts that
(1) %z is not portable to pre-C99 systems, and
(2) %z doesn't actually act differently from %Z on Windows anyway.

Per failures on buildfarm member hamerkop.

While at it, centralize the code defining what strftime format we
want to use in pg_dump; three copies of that string seems a bit much.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/bin/pg_dump/dumputils.h b/src/bin/pg_dump/dumputils.h
index 688e9ca6b82..aaf40748524 100644
--- a/src/bin/pg_dump/dumputils.h
+++ b/src/bin/pg_dump/dumputils.h
@@ -49,6 +49,23 @@ typedef struct SimpleStringList
 
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))
 
+/*
+ * Preferred strftime(3) format specifier for printing timestamps in pg_dump
+ * and friends.
+ *
+ * We don't print the timezone on Windows, because the names are long and
+ * localized, which means they may contain characters in various random
+ * encodings; this has been seen to cause encoding errors when reading the
+ * dump script.  Think not to get around that by using %z, because
+ * (1) %z is not portable to pre-C99 systems, and
+ * (2) %z doesn't actually act differently from %Z on Windows anyway.
+ */
+#ifndef WIN32
+#define PGDUMP_STRFTIME_FMT  "%Y-%m-%d %H:%M:%S %Z"
+#else
+#define PGDUMP_STRFTIME_FMT  "%Y-%m-%d %H:%M:%S"
+#endif
+
 extern int	quote_all_identifiers;
 extern PQExpBuffer (*getLocalPQExpBuffer) (void);