[Gambas-bugtracker] Bug #2291: On a process streams peek seems to advances the read pointer

[bugtracker at gambaswiki.org]

http://gambaswiki.org/bugtracker/edit?object=BUG.2291&from=L21haW4-

Brian G reported a new bug.

Summary
-------

On a process streams peek seems to advances the read pointer

Type             : Bug
Priority         : High
Gambas version   : Master
Product          : Language


Description
-----------

While testing the util package process.expect extension

Where the ProcessExpect class does a 

   sData = Peek #hProcess, lof(hProcess)

       changed it to the folowing for testing as the above gets an eof error on the second read

   sData = Peek #hProcess, -254 'rlen i changed this because it always gets a eof error otherwise on the second read event

Two things occur after the first read it gets a eof error so changing it to -254 so that would not crash
it looks like the peek is advancing the read pointer and somehow that screws up the second peek
also chunks of data never make it to the read event.

This much seems to work using EXEC

but if I use Shell it never receives anything.

I hope this helps

I attach a test program


System information
------------------

[System]
Gambas=3.16.90 feb39623d (CreateInitialgb.scripter-convertGBS3later)
OperatingSystem=Linux
Kernel=5.8.0-55-generic
Architecture=x86_64
Distribution=Linux Mint 20.1 Ulyssa
Desktop=MATE
Font=Ubuntu,10
Scale=7
Theme=mint-y
Language=en_US.UTF-8
Memory=14013M

[Libraries]
Cairo=libcairo.so.2.11600.0
Curl=libcurl.so.4.6.0
DBus=libdbus-1.so.3.19.11
GDK2=libgdk-x11-2.0.so.0.2400.32
GDK3=libgdk-3.so.0.2404.16
GStreamer=libgstreamer-1.0.so.0.1602.0
GTK+2=libgtk-x11-2.0.so.0.2400.32
GTK+3=libgtk-3.so.0.2404.16
OpenGL=libGL.so.1.7.0
Poppler=libpoppler.so.97.0.0
QT5=libQt5Core.so.5.12.8
SDL=libSDL-1.2.so.0.11.4
SQLite=libsqlite3.so.0.8.6

[Environment]
CLUTTER_BACKEND=x11
COMPIZ_CONFIG_PROFILE=mint
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
DESKTOP_SESSION=mate
DISPLAY=:0
EDITOR=/usr/bin/nano
GB_GUI=gb.gtk3
GDMSESSION=mate
GDM_LANG=en_US
GIO_LAUNCHED_DESKTOP_FILE_PID=2719850
GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
GTK3_MODULES=xapp-gtk3-module
GTK_MODULES=gail:atk-bridge
GTK_OVERLAY_SCROLLING=0
HOME=<home>
LANG=en_US.UTF-8
LANGUAGE=en_US.UTF-8
LC_ALL=en_US.UTF-8
LOGNAME=<user>
MATE_DESKTOP_SESSION_ID=this-is-deprecated
PATH=<home>/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
PWD=<home>
QT_ACCESSIBILITY=1
QT_AUTO_SCREEN_SCALE_FACTOR=0
QT_LOGGING_RULES=*.debug=false
QT_QPA_PLATFORMTHEME=qt5ct
QT_SCALE_FACTOR=1
SESSION_MANAGER=local/<hostname>:@/tmp/.ICE-unix/2336200,unix/<hostname>:/tmp/.ICE-unix/2336200
SHELL=/usr/bin/gsh
SHLVL=0
SSH_AGENT_PID=2336336
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
TERM=xterm
TZ=:/etc/localtime
USER=<user>
XAUTHORITY=<home>/.Xauthority
XDG_CONFIG_DIRS=/etc/xdg/xdg-mate:/etc/xdg
XDG_CURRENT_DESKTOP=MATE
XDG_DATA_DIRS=/usr/share/mate:<home>/.local/share/flatpak/exports/share:/var/lib/flatpak/exports/share:/usr/local/share:/usr/share
XDG_GREETER_DATA_DIR=/var/lib/lightdm-data/<user>
XDG_RUNTIME_DIR=/run/user/1000
XDG_SEAT=seat0
XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
XDG_SESSION_CLASS=user
XDG_SESSION_DESKTOP=mate
XDG_SESSION_ID=c6
XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session2
XDG_SESSION_TYPE=x11
XDG_VTNR=7