dqlite will core dump if you put an invalid type in a column

[SimonRichardson]

If for any reason you put an incorrect value in a column that isn't of the same type, dqlite will core dump.

Core dumps are currently non-recoverable, so this is extremely problematic.

The offending lines:

dqlite/src/query.c

Lines 7 to 30 in 7a37bdf

	static int value_type(sqlite3_stmt *stmt, int i)
	{
	int type = sqlite3_column_type(stmt, i);
	const char *column_type_name = sqlite3_column_decltype(stmt, i);
	if (column_type_name != NULL) {
	if ((strcasecmp(column_type_name, "DATETIME") == 0) ||
	(strcasecmp(column_type_name, "DATE") == 0) ||
	(strcasecmp(column_type_name, "TIMESTAMP") == 0)) {
	if (type == SQLITE_INTEGER) {
	type = DQLITE_UNIXTIME;
	} else {
	assert(type == SQLITE_TEXT ||
	type == SQLITE_NULL);
	type = DQLITE_ISO8601;
	}
	} else if (strcasecmp(column_type_name, "BOOLEAN") == 0) {
	assert(type == SQLITE_INTEGER || type == SQLITE_NULL);
	type = DQLITE_BOOLEAN;
	}
	}
	assert(type < 16);
	return type;
	}

In sqlite this will return the type regardless of the value. I think dqlite should follow what sqlite does here.

Note: if we compile in release mode, it prevents us from identifying other problems/issues.