Re-land "Return pdfium::span<char> from ByteString::GetBuffer().""

This reverts commit 3d523e3cf89440e2ffc6571b1c687ad5e3f0318f.
Fixes bounding errors now caught by tests.

Change-Id: I4d0f1791bdcc45a10615a62abf7a4d20e7e538f2
Reviewed-on: https://pdfium-review.googlesource.com/30799
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 11 insertions, 10 deletions

diff --git a/core/fxcrt/bytestring_unittest.cpp b/core/fxcrt/bytestring_unittest.cpp
index f7e1559af9..d030535edd 100644
--- a/core/fxcrt/bytestring_unittest.cpp
+++ b/core/fxcrt/bytestring_unittest.cpp
@@ -843,22 +843,23 @@ TEST(ByteString, Reserve) {
 }
 
 TEST(ByteString, GetBuffer) {
+  ByteString str1;
   {
-    ByteString str;
-    char* buffer = str.GetBuffer(12);
+    pdfium::span<char> buffer = str1.GetBuffer(12);
     // NOLINTNEXTLINE(runtime/printf)
-    strcpy(buffer, "clams");
-    str.ReleaseBuffer(str.GetStringLength());
-    EXPECT_EQ("clams", str);
+    strcpy(buffer.data(), "clams");
   }
+  str1.ReleaseBuffer(str1.GetStringLength());
+  EXPECT_EQ("clams", str1);
+
+  ByteString str2("cl");
   {
-    ByteString str("cl");
-    char* buffer = str.GetBuffer(12);
+    pdfium::span<char> buffer = str2.GetBuffer(12);
     // NOLINTNEXTLINE(runtime/printf)
-    strcpy(buffer + 2, "ams");
-    str.ReleaseBuffer(str.GetStringLength());
-    EXPECT_EQ("clams", str);
+    strcpy(&buffer[2], "ams");
   }
+  str2.ReleaseBuffer(str2.GetStringLength());
+  EXPECT_EQ("clams", str2);
 }
 
 TEST(ByteString, ReleaseBuffer) {