Dear SQLite developers,

From version 3.43, I see what appears to be incorrect rounding when using the f and g conversions with precision 0 in the format() function:


> SELECT format('%0.0f', 0.9);
--SQLite version 3.42.0
1 --ok
--SQLite version 3.45.1
0 --wrong


> SELECT format('%0.0g', 0.09);
--SQLite version 3.42.0
0.09 --ok
--SQLite version 3.45.1
0.08 -- wrong

> SELECT format('%0.0g', 1.9);
--SQLite version 3.42.0
2 --ok
--SQLite version 3.45.1
1 --wrong

Regarding the %g conversion, there is the additional question of what 0 precision means. According to https://sqlite.org/printf.html:

"For floating-point substitutions (%e, %E, %f, %g, %G) the precision specifies the number of digits to display to the right of the decimal point."

I assume this to be a documentation error because, in practice, SQLite %g appears to follow C printf %g where precision specifies the number of significant digits.

Given that precision for %g specifies the number of significant digits, the meaning of 0 precision may not be obvious, but at least this source explicitly states that 0 precision is treated the same as 1:
  https://en.cppreference.com/w/c/io/fprintf
SQLite agrees, except for "buggy" cases like the ones above.