[PATCH 2/2] pack-format.txt: document lengths at start of delta data

["Martin Ågren" <martin.agren@gmail.com>]

We document the delta data as a set of instructions, but forget to
document the two lengths that precede those instructions: the length of
the base object and the length of the object to be reconstructed. Fix
this omission.

Reported-by: Ross Light <ross@zombiezen.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
 Documentation/technical/pack-format.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt
index 42198de74c..05889a2e43 100644
--- a/Documentation/technical/pack-format.txt
+++ b/Documentation/technical/pack-format.txt
@@ -82,7 +82,10 @@ Ref-delta can also refer to an object outside the pack (i.e. the
 so-called "thin pack"). When stored on disk however, the pack should
 be self contained to avoid cyclic dependency.
 
-The delta data is a sequence of instructions to reconstruct an object
+The delta data starts with the length of the base object and the
+length of the object to be reconstructed. These lengths are
+encoded as varints.  The remainder of
+the delta data is a sequence of instructions to reconstruct the object
 from the base object. If the base object is deltified, it must be
 converted to canonical form first. Each instruction appends more and
 more data to the target object until it's complete. There are two
-- 
2.30.0.rc1