Write NULL as "" so readString() always returns a non-NULL string.

Write NULL as "" so readString() always returns a non-NULL string.

BUG=
R=reed@google.com

Committed: https://code.google.com/p/skia/source/detail?r=10754

[reed1, 2013-08-12 17:05:47]

nits, but lgtm

https://codereview.chromium.org/22862002/diff/1/src/core/SkWriter32.cpp
File src/core/SkWriter32.cpp (right):

https://codereview.chromium.org/22862002/diff/1/src/core/SkWriter32.cpp#newco...
src/core/SkWriter32.cpp:272: this->writeString("");
since no 2nd parameter implies a call to strlen, etc., perhaps we should just
setup the  params correctly and fall through...

if (NULL == str) {
    len = 0;
    // fall through, ... or 
    this->write32(0);
    return;
}

Its a nit I know, and yours is very readable, but having the recursive call
seems slightly overkill for such a lean-and-mean lib as ours :)

[mtklein, 2013-08-12 17:20:03]

https://codereview.chromium.org/22862002/diff/1/src/core/SkWriter32.cpp
File src/core/SkWriter32.cpp (right):

https://codereview.chromium.org/22862002/diff/1/src/core/SkWriter32.cpp#newco...
src/core/SkWriter32.cpp:272: this->writeString("");
On 2013/08/12 17:05:47, reed1 wrote:
> since no 2nd parameter implies a call to strlen, etc., perhaps we should just
> setup the  params correctly and fall through...
> 
> if (NULL == str) {
>     len = 0;
>     // fall through, ... or 
>     this->write32(0);
>     return;
> }
> 
> Its a nit I know, and yours is very readable, but having the recursive call
> seems slightly overkill for such a lean-and-mean lib as ours :)

Here's a third option, neither overkill nor unreadable?

[reed1, 2013-08-12 17:36:20]

https://codereview.chromium.org/22862002/diff/6001/src/core/SkWriter32.cpp
File src/core/SkWriter32.cpp (right):

https://codereview.chromium.org/22862002/diff/6001/src/core/SkWriter32.cpp#ne...
src/core/SkWriter32.cpp:272: str = "";
add 

len = 0;

and we have a deal :)

[mtklein, 2013-08-12 17:39:14]

https://codereview.chromium.org/22862002/diff/6001/src/core/SkWriter32.cpp
File src/core/SkWriter32.cpp (right):

https://codereview.chromium.org/22862002/diff/6001/src/core/SkWriter32.cpp#ne...
src/core/SkWriter32.cpp:272: str = "";
On 2013/08/12 17:36:21, reed1 wrote:
> add 
> 
> len = 0;
> 
> and we have a deal :)

Done.

[mtklein, 2013-08-15 21:01:39]

Committed patchset #3 manually as r10754 (presubmit successful).