PDF: Fix extra NUL characters from incorrect WriteInto() calls.

pdf/pdfium/pdfium_page.cc

Index: pdf/pdfium/pdfium_page.cc
diff --git a/pdf/pdfium/pdfium_page.cc b/pdf/pdfium/pdfium_page.cc
index cd75a1bc3716982bdbcb06ff3707d8f80183ba8a..adf9cac484bfd1334da8f69c38e491fa6760517c 100644
--- a/pdf/pdfium/pdfium_page.cc
+++ b/pdf/pdfium/pdfium_page.cc
@@ -324,7 +324,7 @@ PDFiumPage::Area PDFiumPage::GetLinkTarget(
             size_t buffer_size =
                 FPDFAction_GetURIPath(engine_->doc(), action, NULL, 0);
             if (buffer_size > 1) {
-              void* data = WriteInto(&target->url, buffer_size + 1);
+              void* data = WriteInto(&target->url, buffer_size);
               FPDFAction_GetURIPath(engine_->doc(), action, data, buffer_size);
             }
           }
@@ -406,7 +406,7 @@ void PDFiumPage::CalculateLinks() {
   for (int i = 0; i < count; ++i) {
     base::string16 url;
     int url_length = FPDFLink_GetURL(links, i, NULL, 0);
-    if (url_length > 1) {  // WriteInto needs at least 2 characters.
+    if (url_length > 0) {
       unsigned short* data =
           reinterpret_cast<unsigned short*>(WriteInto(&url, url_length + 1));

[raymes, 2015/01/14 00:13:12]

I just had another look at this and I think that we should keep the > 1 above
and remove the + 1 here. The reason is that FPDFLink_GetURL seems to return a
value which /includes/ the null terminator. WDYT?

[Lei Zhang, 2015/01/14 01:21:54]

Gah! I will make another CL...

[Deepak, 2015/01/14 03:50:38]

I personally don't think that FPDFLink_GetURL() gives me len that have null
character included.
as 
int len= cbUTF16URL.GetLength()/sizeof(unsigned short);
This does not include null terminator.
with the previous code we just need to add null terminator in the last, as we
are passing 1 extra in the url_length.

       FPDFLink_GetURL(links, i, data, url_length);