Safer IsText option.

johnno1962 · johnno1962 · commit 198d9b08934a · 2025-09-15T09:36:14.000+02:00
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
@@ -509,7 +509,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
       // from the page cache that are not properly filled with trailing zeroes,
       // if some prior user of the page wrote non-zero bytes. Detect this and
       // don't use mmap in that case.
-      if (!IsText || *Result->getBufferEnd() == '\0')
+      if (!IsText || !RequiresNullTerminator || *Result->getBufferEnd() == '\0')
         return std::move(Result);
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -509,7 +509,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,`
`509`	`509`	`// from the page cache that are not properly filled with trailing zeroes,`
`510`	`510`	`// if some prior user of the page wrote non-zero bytes. Detect this and`
`511`	`511`	`// don't use mmap in that case.`
`512`		`- if (!IsText \|\| *Result->getBufferEnd() == '\0')`
	`512`	`+ if (!IsText \|\| !RequiresNullTerminator \|\| *Result->getBufferEnd() == '\0')`
`513`	`513`	`return std::move(Result);`
`514`	`514`	`}`
`515`	`515`	`}`