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diff --git a/src/docs/read_zero_byte_vec.txt b/src/docs/read_zero_byte_vec.txt
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+### What it does
+This lint catches reads into a zero-length `Vec`.
+Especially in the case of a call to `with_capacity`, this lint warns that read
+gets the number of bytes from the `Vec`'s length, not its capacity.
+
+### Why is this bad?
+Reading zero bytes is almost certainly not the intended behavior.
+
+### Known problems
+In theory, a very unusual read implementation could assign some semantic meaning
+to zero-byte reads. But it seems exceptionally unlikely that code intending to do
+a zero-byte read would allocate a `Vec` for it.
+
+### Example
+```
+use std::io;
+fn foo<F: io::Read>(mut f: F) {
+    let mut data = Vec::with_capacity(100);
+    f.read(&mut data).unwrap();
+}
+```
+Use instead:
+```
+use std::io;
+fn foo<F: io::Read>(mut f: F) {
+    let mut data = Vec::with_capacity(100);
+    data.resize(100, 0);
+    f.read(&mut data).unwrap();
+}
+```
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