fix: correct issue where gas simulation can't be made with --generate-only flag

[ejfitzgerald]

Updated SDK logic to correctly query the account number and sequence when simulating transactions using the --generate-only flag

[daeMOn63]

Checked v0.45 and it doesn't have the bug (they've updated CalculateGas)
Otherwise lgtm, not really sure why updatedTxf was introduced, it doesn't seem necessary at first sight, should be ok to assign back to txf directly

[ejfitzgerald]

Checked v0.45 and it doesn't have the bug (they've updated CalculateGas) Otherwise lgtm, not really sure why updatedTxf was introduced, it doesn't seem necessary at first sight, should be ok to assign back to txf directly

This was an absolute head scratcher for me (and maybe just illustrates my poor understanding of go). When I made the original update I did not introduce updatedTxf, however, this resulted in the calculated gas value not being added to the generated tx. Some Printf-ing later it was the case that the txf here:

https://github.com/fetchai/cosmos-sdk/pull/126/files#diff-51a03bdc40c78352a7e2db8c850e9d2611c70440df997ee92a03215528192b32R66

Seemed to go out of scope and then when the final tx is built (see link below) it used to the original value from the function parameters:

https://github.com/fetchai/cosmos-sdk/pull/126/files#diff-51a03bdc40c78352a7e2db8c850e9d2611c70440df997ee92a03215528192b32R71

(Checked by looking at the underlying pointer values)

Would you expect this @daeMOn63 ?

[daeMOn63]

@ejfitzgerald thanks for the feedback, I overlooked it and this is why you needed updatedTxf:
The := operator will create variable in current scope and assign to them. Changing to:

Suggested change

	txf, err := PrepareFactory(clientCtx, txf)
	var err error
	txf, err = PrepareFactory(clientCtx, txf)

make it reuse the txf from the parent scope. But then we have to declare err since it doesn't exist yet.

[ejfitzgerald]

Ah yes of course. I just didn't spot that! Nice one