[12] RFR: 8214777: Avoid some GCC 8.X strncpy() errors in HotSpot

[Kim Barrett]

> On Dec 10, 2018, at 1:57 PM, Simon Tooke <stooke at redhat.com> wrote:
> 
> This small patch fixes some simple warnings in Hotspot code, found by
> GCC 8.1
> 
> Essentially, any code sequence of the pattern
> 
>    int l = strlen(somestring)
>    char* buffer = malloc(l + 1)
>    strncpy(buffer, somestring, l)
>    buffer[l] = 0
> 
> is replaced by
> 
>    int len = strlen(somestring)
>    char* buffer = malloc(len + 1)
>    strncpy(buffer, somestring, len + 1)
> 
> For xmlstream.cpp, this is actually a small inefficiency, as the null
> byte is immediately overwritten; but it makes GCC happy.

Why not just call strcpy, rather than strncpy, since the size is obviously sufficient.

> Bug: https://bugs.openjdk.java.net/browse/JDK-8214777
> Webrev:
> http://cr.openjdk.java.net/~sgehwolf/webrevs/stooke/JDK-8214777/02/webrev/