drvgettable(): fix leaked SQLite statement / persistent lock when SQL_ATTR_MAX_ROWS cap is hit

sqlite3odbc.c

@@ -1587,6 +1587,37 @@ drvgettable(STMT *s, const char *sql, char ***resp, int *nrowp,
 	ncol = sqlite3_column_count(tres.stmt);
 	while (1) {
 	    if (s->max_rows && tres.nrow >= s->max_rows) {
+		/*
+		 * BUGFIX: previously this broke out of the loop
+		 * without finalizing or resetting tres.stmt. The
+		 * outer loop then unconditionally overwrites
+		 * tres.stmt with NULL before preparing the next
+		 * statement, silently orphaning the still-open
+		 * SQLite statement handle -- no C-level reference is
+		 * left to ever finalize it. An orphaned, unfinalized
+		 * statement keeps holding its SQLite-level lock for
+		 * as long as the connection stays open, completely
+		 * independent of any BEGIN/COMMIT/autocommit state.
+		 * This matches a client hitting a row-count cap
+		 * (SQL_ATTR_MAX_ROWS) on a table larger than that
+		 * cap: the resulting held lock would block every
+		 * other process from writing to the file until the
+		 * connection holding the leaked statement fully
+		 * closes. Route through the same
+		 * finalize-or-reset-then-advance cleanup used by the
+		 * normal completion path below instead of skipping
+		 * it.
+		 */
+		if (keep) {
+		    dbtraceapi(d, "sqlite3_reset", 0);
+		    rc = sqlite3_reset(tres.stmt);
+		    s->s3stmt_noreset = 1;
+		} else {
+		    dbtraceapi(d, "sqlite3_finalize", 0);
+		    rc = sqlite3_finalize(tres.stmt);
+		}
+		tres.stmt = 0;
+		sql = NULL;
 		rc = SQLITE_OK;
 		break;
 	    }