Fix an assortment of improper usages of string functions

In a similar effort to f736e188c and 110d81728, fixup various usages of
string functions where a more appropriate function is available and more
fit for purpose.

These changes include:

1. Use cstring_to_text_with_len() instead of cstring_to_text() when
   working with a StringInfoData and the length can easily be obtained.
2. Use appendStringInfoString() instead of appendStringInfo() when no
   formatting is required.
3. Use pstrdup(...) instead of psprintf("%s", ...)
4. Use pstrdup(...) instead of psprintf(...) (with no formatting)
5. Use appendPQExpBufferChar() instead of appendPQExpBufferStr() when the
   length of the string being appended is 1.
6. appendStringInfoChar() instead of appendStringInfo() when no formatting
   is required and string is 1 char long.
7. Use appendPQExpBufferStr(b, .) instead of appendPQExpBuffer(b, "%s", .)
8. Don't use pstrdup when it's fine to just point to the string constant.

I (David) did find other cases of #8 but opted to use #4 instead as I
wasn't certain enough that applying #8 was ok (e.g in hba.c)

Author: Ranier Vilela, David Rowley
Discussion: https://postgr.es/m/CAApHDvo2j2+RJBGhNtUz6BxabWWh2Jx16wMUMWKUjv70Ver1vg@mail.gmail.com

1 files changed, 1 insertions, 1 deletions

diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
index d35b5d1f4f..6c45fd2007 100644
--- a/src/backend/utils/adt/misc.c
+++ b/src/backend/utils/adt/misc.c
@@ -219,7 +219,7 @@ pg_tablespace_databases(PG_FUNCTION_ARGS)
 	}
 
 	if (tablespaceOid == DEFAULTTABLESPACE_OID)
-		location = psprintf("base");
+		location = "base";
 	else
 		location = psprintf("pg_tblspc/%u/%s", tablespaceOid,
 							TABLESPACE_VERSION_DIRECTORY);