From: Matt Beaumont-Gay <matthewbg@google.com>
Date: Tue, 12 Mar 2013 23:55:24 +0000 (+0000)
Subject: Don't crash if write_impl() leaves less buffer space available than expected.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=b79d25ca9c3b895d8fdc88c3acefec1202ca9da3;p=oota-llvm.git

Don't crash if write_impl() leaves less buffer space available than expected.

This was tickled by a Clang diagnostic; Clang test case to follow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176911 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Support/raw_ostream.cpp b/lib/Support/raw_ostream.cpp
index f71abd3b244..da26a371a76 100644
--- a/lib/Support/raw_ostream.cpp
+++ b/lib/Support/raw_ostream.cpp
@@ -306,7 +306,12 @@ raw_ostream &raw_ostream::write(const char *Ptr, size_t Size) {
     if (LLVM_UNLIKELY(OutBufCur == OutBufStart)) {
       size_t BytesToWrite = Size - (Size % NumBytes);
       write_impl(Ptr, BytesToWrite);
-      copy_to_buffer(Ptr + BytesToWrite, Size - BytesToWrite);
+      size_t BytesRemaining = Size - BytesToWrite;
+      if (BytesRemaining > size_t(OutBufEnd - OutBufCur)) {
+        // Too much left over to copy into our buffer.
+        return write(Ptr + BytesToWrite, BytesRemaining);
+      }
+      copy_to_buffer(Ptr + BytesToWrite, BytesRemaining);
       return *this;
     }