Re: Minor issues in .pgpass - Mailing list pgsql-hackers

On 2020/03/03 21:38, Hamid Akhtar wrote:
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> On Mon, Mar 2, 2020 at 6:07 PM Fujii Masao <masao.fujii@oss.nttdata.com <mailto:masao.fujii@oss.nttdata.com>> wrote:
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>     On 2020/02/29 0:46, Hamid Akhtar wrote:
>      > The following review has been posted through the commitfest application:
>      > make installcheck-world:  not tested
>      > Implements feature:       not tested
>      > Spec compliant:           not tested
>      > Documentation:            not tested
>      >
>      > First of all, this seems like fixing a valid issue, albeit, the probability of somebody messing is low, but it is still better to fix this problem.
>      >
>      > I've not tested the patch in any detail, however, there are a couple of comments I have before I proceed on with detailed testing.
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>     Thanks for the review and comments!
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>      > 1. pgindent is showing a few issues with formatting. Please have a look and resolve those.
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>     Yes.
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>      > 2. I think you can potentially use "len" variable instead of introducing "buflen" and "tmplen" variables.
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>     Basically I don't want to use the same variable for several purposes
>     because which would decrease the code readability.
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>      > Also, I would choose a more appropriate name for "tmp" variable.
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>     Yeah, so what about "rest" as the variable name?
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>      > I believe if you move the following lines before the conditional statement and simply and change the if statement to "if (len >= sizeof(buf) - 1)", it will serve the purpose.
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>     ISTM that this doesn't work correctly when the "buf" contains
>     trailing carriage returns but not newlines (i.e., this line is too long
>     so the "buf" doesn't include newline). In this case, pg_strip_crlf()
>     shorten the "buf" and then its return value "len" should become
>     less than sizeof(buf). So the following condition always becomes
>     false unexpectedly in that case even though there is still rest of
>     the line to eat.
>
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> Per code comments for pg_strip_crlf:
> "pg_strip_crlf -- Remove any trailing newline and carriage return"
> If the buf read contains a newline or a carriage return at the end, then clearly the line
> is not exceeding the sizeof(buf).

No if the length of the setting line exceeds sizeof(buf) and
the buf contains only a carriage return at the end and not newline.
This case can happen because fgets() stops reading when a newline
(not a carriage return) is found. Normal users are very unlikely to
add a carriage return into the middle of the pgpass setting line
in practice, though. But IMO the code should handle even this
case because it *can* happen, if the code is not so complicated.

Regards,


--
Fujii Masao
NTT DATA CORPORATION
Advanced Platform Technology Group
Research and Development Headquarters