Fixed off-by-one error #3
Open
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Always zero out the whole 40 byte buffer of stringin and transmit only 39 bytes if requested length is 40. This way we make sure that the resulting string is always null terminated even if the PLC sends a non-terminated one. It also means that the effective maximum string length is 39.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
With L==40, the terminating null byte was written after the end of VAL right into OVAL (continuously triggering a monitor). The proposed fix is more general than a simple "- 1":
Always zero out the whole 40 byte buffer of stringin and transmit only
39 bytes if requested length is 40. This way we make sure that the
resulting string is always null terminated even if the PLC sends a
non-terminated one. It also means that the effective maximum string
length is 39.