RFR: JDK-8312612: handle WideCharToMultiByte return values

[Matthias Baesken]

On Fri, 28 Jul 2023 08:23:35 GMT, Christoph Langer <clanger at openjdk.org> wrote:

>> The function WideCharToMultiByte is used at a number of places of the JDK codebase for conversion purposes.
>> Unfortunately, the function might fail because of various reasons, so the return value must be checked to avoid undefined behavior or even crashes.
>> see
>> https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte
>> especially
>> https://learn.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringapiset-widechartomultibyte#return-value
>> 
>> At most places in the coding the return values are already checked, but some are missing.
>
> src/java.desktop/windows/native/libawt/windows/awt_PrintJob.cpp line 3933:
> 
>> 3931:         JNU_ThrowByName(env, PRINTEREXCEPTION_STR, errStr);
>> 3932:     } else {
>> 3933:         JNU_ThrowByName(env, PRINTEREXCEPTION_STR, "Secondary error while OS message extraction");
> 
> better: secondary error during OS message extraction

I borrowed it from here  (other error handling of WideCharToMultiByte) 


jdk/src/java.base/windows/native/libjava/ProcessImpl_md.c 

102          const char *errorMessage = "Secondary error while OS message extraction";


should I change both locations ?

> src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_Charset_Util.cpp line 46:
> 
>> 44:         delete[] lpUTF8Str;
>> 45:     }
>> 46:     return NULL;
> 
> better move `return NULL` into else block?

Better remove the else block :-) ?

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PR Review Comment: https://git.openjdk.org/jdk/pull/15015#discussion_r1277339373
PR Review Comment: https://git.openjdk.org/jdk/pull/15015#discussion_r1277340457