Unable to execute transactions on Free Gas Networks

[lukeskywlkr]

Describe the bug
The application is unable to execute transactions with gas price set to 0 on free gas networks. Metamask reports 0 as invalid number.

Screenshots

To Reproduce
Steps to reproduce the behavior

1. Connect to a Free Gas Network
2. Execute a transaction and try to set the gas price to 0
3. See error

Expected behavior
The app should allow the execution of a transaction on a free gas network and let the user modify accordingly the advanced transaction fee settings.

Smartphone (please complete the following information):

• Device: iPhone6s
• OS: iOS 14.0.1
• App Version v1.0.3 (528)

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to be added after bug submission by internal support / PM
Severity

• How critical is the impact of this bug on a user?
• Add stats if available on % of customers impacted
• Is this visible to all users?
• Is this tech debt?

[lukeskywlkr]

Seems that the error is generated by this check at this line of code:

metamask-mobile/app/components/Views/SendFlow/CustomGas/index.js

Line 395 in 19593ce

if (value === '0' || !value || value === '' || !isDecimal(value)) {

Could it be problematic to allow execution of transactions on such networks?

[ackhia]

Seems like this change was made in PR #1750 and has broken compatibility with Quorum and possibly other private network focused implementations.

[Obafs]

What advantage was obtained by making this change? In my current use, it prevents mobile users from accessing smart contract methods on private networks, that are available to the desktop version.

TL;DR: Please allow zero in custom gas price, unless there is a security reason not to.

[github-actions]

This issue was closed because it has been stalled for 7 days with no activity. If you feel this was closed in error please reopen and provide evidence on the current production app. Thank you for your contributions.