c: Fix prototype generator when last argument is a BufferIn

We were passing the name of the last argument directly to va_start. However, if
the last argument is a BufferIn it expands to 2 arguments, the latter of which
is <name>_size.
(cherry picked from commit 3d80161d9c277c800a3214694ba56a8909e655df)

1 files changed, 7 insertions, 1 deletions

diff --git a/generator/generator_c.ml b/generator/generator_c.ml
index e9fe89b6..51bcf849 100644
--- a/generator/generator_c.ml
+++ b/generator/generator_c.ml
@@ -1400,7 +1400,13 @@ trace_send_line (guestfs_h *g)
           | _ ->
               match args with
               | [] -> "g"
-              | args -> name_of_argt (List.hd (List.rev args)) in
+              | args ->
+                let last = List.hd (List.rev args) in
+                let name = name_of_argt last in
+                match last with
+                | BufferIn n -> name ^ "_size"
+                | _ -> name
+        in
 
         let rtype =
           match ret with