SQLite

Consider the following statement:

<code>
SELECT 1 % '1E1'; -- expected: {1.0}, actual: {0.0}
</code>

Unexpectedly, the result is 0.0. This seems to be a regression bug that was introduced by [048add13fc10e69a], and was found by SQLancer's PQS implementation based on commit [6c716f4b55].

The intent of the "%" operator is to work on integers only.  For any values
$A and $B, the following should always be true:

>  `($A % $B) == (CAST($A AS INT) % CAST($B AS INT))`

This fact is not clearly defined in the documentation, but it has always
been so.  I will use this ticket to enhance the documentation.
The behavior of `CAST($A as INT)` when $A is a string is well-defined in
the documentation.  It says:

> "When casting a TEXT value to INTEGER, the longest possible prefix of the value that can be interpreted as an integer number is extracted from the TEXT value and the remainder ignored."

The longest possible prefix of the string "`'1e1'`" that can be interpreted
as an integer is "`'1'`".  Hence `CAST('1e1' as INT)` yields 1, not 10.
Check-in [](048add13fc10e69a) was a bug fix to make the implicit CAST
operation on the operands of "%" work correctly.

Documentation updated.  <https://www.sqlite.org/docsrc/info/153857859d220dbd>