Incorrect handling of longtext MySQL fields

[antirix-dev]

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Environment

• Operating System version:
• Game/AppID (with version if applicable):
• Current SourceMod version:
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• Current Metamod: Source snapshot:

• I have updated SourceMod to the latest version and it still happens.
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• I have updated SourceMM to the latest snapshot and it still happens.

Description

Consider the following:

1. A table contains a longtext field.
2. A query retrieves a single row, including that field.
3. SQL_FetchString is used to read the field into a buffer of a length smaller than the longtext maximum length, but larger than the actual data due to be retrieved
4. This will result in an error

It appears that the code incorrectly bails upon determining that the buffer wouldn't be able to hold the maximum possible size of the longtext field - though that is irrelevant as it actually could hold the data in the scenario in question.

Problematic Code (or Steps to Reproduce)

Database db;
// ... code to connect to database
DBStatement stmt = SQL_PrepareQuery(db, "<sql here to select * from table with longtext field limit 1>", error, errorSize);
SQL_Execute(stmt);
SQL_FetchRow(stmt)
char buf[length larger than the actual data in the field];
SQL_FetchString(stmt, <field index>, buf, sizeof(buf));

Error: Exception reported: Could not fetch data in field <field index> as a string

Logs

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• In case of a crash, please attach minidump or dump analyze output.