On 30/10/2026 08:59, Jeevan Chalke wrote:
read_sql_construct() in pl_gram.y takes up to three terminator tokens.
Callers pass 0 for the ones they don't use, but 0 is also the token code
for end of input. The loop compares against until2 and until3 before it
gets to its own "tok == 0" check, which is what produces the
missing "%s" at end of SQL expression/statement
error.
So when a function body ends in the middle of a construct, EOF is taken
as a valid terminator and the helpful message is skipped. The text read
so far is then handed to the core parser or the next grammar rule, which
reports something generic or misleading:
do $$ begin if true $$;
ERROR: syntax error at end of input
do $$ begin while true $$;
ERROR: syntax error at end of input
do $$ begin case 1 $$;
ERROR: missing expression at end of input
do $$ declare x int; begin x := 1 $$;
ERROR: syntax error at end of input
The attached patch only compares against until2/until3 when they are
non-zero (until is always non-zero for every caller). With it:
do $$ begin if true $$;
ERROR: missing "THEN" at end of SQL expression
do $$ begin while true $$;
ERROR: missing "LOOP" at end of SQL expression
do $$ begin case 1 $$;
ERROR: missing "WHEN" at end of SQL expression
do $$ declare x int; begin x := 1 $$;
ERROR: missing ";" at end of SQL statement
The error position is the same as before (end of input).
Nice catch.
I added the four statements above to plpgsql.sql; no existing
expected output changes.
I moved the tests to src/plpgsql/src/sql/plpgsql_misc.sql. The division
isn't totally clear, but I think the main suite's plpgsql.sql is more
geared towards for PL/pgSQL's interactions with the rest of the system,
and the tests in src/plpgsql/src/ are more for pl/pgSQL's internal
business. I also removed two of those variants as redundant; they all
reach the same codepath in read_sql_construct() function in the end.
Since this only changes error message text, which tests and external
tools may match on, I think master only is the safer choice (or v19 as
it is not yet released), but I'm happy to hear
other opinions.
Committed to master, thanks!
- Heikki
