[LEDE-DEV] [PATCH] fstools: Fix some errors detected by cppcheck

[Arjen de Korte]

Citeren Jonas Gorski <jonas.gorski at gmail.com>:

> On 11 December 2017 at 10:04, Rosen Penev <rosenp at gmail.com> wrote:
>> Mainly plugging memory leaks. Size reduction as well. The calloc  
>> change accounts for 272 bytes on this machine for some reason...
>
> Please state the exact errors found by cppcheck so we don't have to
> guess what it found.

I tried to replicate what Rosen did, but in my case cppcheck came up  
with only two errors:

     [libfstools/rootdisk.c:175]: (error) Resource leak: f
     [libfstools/ubi.c:72]: (error) Resource leak: f

These look like actual leaks, so this *may* be worth fixing. It could  
also be the conditions never occur (so these never leak anything). The  
proposed changes for these two errors look sane though.

     [block.c:1087] -> [block.c:1091]: (warning) Either the condition  
'!pr' is redundant or there is possible null pointer dereference: pr.

This one has merit too. There is no point in doing a NULL pointer  
check after using that pointer a few lines before.

     [blockd.c:119]: (warning) Possible null pointer dereference: device
     [blockd.c:127]: (warning) Possible null pointer dereference: device
     [blockd.c:130]: (warning) Possible null pointer dereference: device

I'm not so sure about these warnings. It doesn't seem possible that  
*both* device_n and device_o are NULL, which would be required to  
actually cause a NULL pointer dereference here. This might be fixed  
cleaner by changing

    211          } else {

to

    211          } else if (device_o) {

The remainder of the warnings might be 'fixed' to shut-up cppcheck,  
but don't actually change anything.