doc: increase Buffer.concat() documentation

cjihrig · MylesBorins · commit a7869541e440 · 2017-07-11T17:43:45.000+01:00
This commit adds documentation for two edge cases in Buffer.concat(). Those cases are: - totalLength is specified, but is not an integer. - The combined buffer length is greater than totalLength. PR-URL: #11845 Fixes: #11605 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/doc/api/buffer.md b/doc/api/buffer.md
@@ -684,6 +684,10 @@ in `list`. This however causes an additional loop to be executed in order to
 calculate the `totalLength`, so it is faster to provide the length explicitly if
 it is already known.
 
+If `totalLength` is provided, it is coerced to an unsigned integer. If the
+combined length of the `Buffer`s in `list` exceeds `totalLength`, the result is
+truncated to `totalLength`.
+
 Example: Create a single `Buffer` from a list of three `Buffer` instances
 
 ```js
