[Libguestfs] [PATCH] Don't include control characters in BufferIn trace output

Certain API calls, pwrite-device is an example, take a BufferIn as an argument which may contain arbitrary binary data. If trace output is on, we will attempt to print this to the terminal. As well as not working properly due to embedded NUL characters, this can cause problems on the output terminal, is unlikely to be useful, and can't be entered into guestfish in any case. This patch scans BufferIn arguments if trace output is on. If it finds any control characters it will replace the entire string with '<data>' in the trace output. --- generator/generator_c.ml | 23 +++++++++++++++++++++-- 1 files changed, 21 insertions(+), 2 deletions(-)