Picom transparency not working on workspaces with only one window

Platform

Arch Linux amd64

GPU, drivers, and screen setup

name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel (0x8086)
    Device: Mesa Intel(R) HD Graphics 620 (KBL GT2) (0x5916)
    Version: 20.1.3
    Accelerated: yes
    Video memory: 3072MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.6
    Max compat profile version: 4.6
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2
OpenGL vendor string: Intel
OpenGL renderer string: Mesa Intel(R) HD Graphics 620 (KBL GT2)
OpenGL core profile version string: 4.6 (Core Profile) Mesa 20.1.3
OpenGL core profile shading language version string: 4.60
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 4.6 (Compatibility Profile) Mesa 20.1.3
OpenGL shading language version string: 4.60
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile

OpenGL ES profile version string: OpenGL ES 3.2 Mesa 20.1.3
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

Environment

i3-gaps

picom version

vgit-e553e

Configuration:

#################################
#             Shadows           #
#################################

# Enabled client-side shadows on windows. Note desktop windows
# (windows with '_NET_WM_WINDOW_TYPE_DESKTOP') never get shadow,
# unless explicitly requested using the wintypes option.
#
# shadow = false
shadow = true

# The blur radius for shadows, in pixels. (defaults to 12)
# shadow-radius = 12
shadow-radius = 7

# The opacity of shadows. (0.0 - 1.0, defaults to 0.75)
shadow-opacity = .75

# The left offset for shadows, in pixels. (defaults to -15)
# shadow-offset-x = -15
shadow-offset-x = -10

# The top offset for shadows, in pixels. (defaults to -15)
# shadow-offset-y = -15
shadow-offset-y = -10

# Red color value of shadow (0.0 - 1.0, defaults to 0).
# shadow-red = 0

# Green color value of shadow (0.0 - 1.0, defaults to 0).
# shadow-green = 0

# Blue color value of shadow (0.0 - 1.0, defaults to 0).
# shadow-blue = 0

# Specify a list of conditions of windows that should have no shadow.
#
# examples:
#   shadow-exclude = "n:e:Notification";
#
# Do not paint shadows on shaped windows. Note shaped windows
# here means windows setting its shape through X Shape extension.
# Those using ARGB background is beyond our control. Use
#   shadow-exclude = 'bounding_shaped'
# or
#   shadow-exclude = 'bounding_shaped && !rounded_corners'
# instead.

shadow-exclude = [
  "name = 'Notification'"
, "name = 'Dunst'"
, "class_g = 'Conky'"
, "class_g ?= 'Notify-osd'"
, "class_g = 'Cairo-clock'"
, "_GTK_FRAME_EXTENTS@:c"
]

# Specify a X geometry that describes the region in which shadow should not
# be painted in, such as a dock window region. Use
#    shadow-exclude-reg = "x10+0+0"
# for example, if the 10 pixels on the bottom of the screen should not have shadows painted on.
#
# shadow-exclude-reg = "x10+0-10"

# Crop shadow of a window fully on a particular Xinerama screen to the screen.
# xinerama-shadow-crop = false

#################################
#           Fading              #
#################################

# Fade windows in/out when opening/closing and when opacity changes,
#  unless no-fading-openclose is used.
# fading = false
fading = false

# Opacity change between steps while fading in. (0.01 - 1.0, defaults to 0.028)
# fade-in-step = 0.028
fade-in-step = 0.03

# Opacity change between steps while fading out. (0.01 - 1.0, defaults to 0.03)
# fade-out-step = 0.03
fade-out-step = 0.03

# The time between steps in fade step, in milliseconds. (> 0, defaults to 10)
# fade-delta = 10

# Specify a list of conditions of windows that should not be faded.
# fade-exclude = []

# Do not fade on window open/close.
no-fading-openclose = true

# Do not fade destroyed ARGB windows with WM frame. Workaround of bugs in Openbox, Fluxbox, etc.
# no-fading-destroyed-argb = false

#################################
#   Transparency / Opacity      #
#################################

# Opacity of inactive windows. (0.1 - 1.0, defaults to 1.0)
inactive-opacity = 0.93

# Opacity of window titlebars and borders. (0.1 - 1.0, disabled by default)
# frame-opacity = 1.0
frame-opacity = 0.7

# Default opacity for dropdown menus and popup menus. (0.0 - 1.0, defaults to 1.0)
# menu-opacity = 0.7

# Let inactive opacity set by -i override the '_NET_WM_OPACITY' values of windows.
# inactive-opacity-override = true
inactive-opacity-override = true

# Default opacity for active windows. (0.0 - 1.0, defaults to 1.0)
# active-opacity = 1.0

# Dim inactive windows. (0.0 - 1.0, defaults to 0.0)
# inactive-dim = 0.0

# Specify a list of conditions of windows that should always be considered focused.
# focus-exclude = []
focus-exclude = [ "class_g = 'Cairo-clock'" ]

# Use fixed inactive dim value, instead of adjusting according to window opacity.
# inactive-dim-fixed = 1.0

# Specify a list of opacity rules, in the format `PERCENT:PATTERN`,
# like `50:name *= "Firefox"`. picom-trans is recommended over this.
# Note we don't make any guarantee about possible conflicts with other
# programs that set '_NET_WM_WINDOW_OPACITY' on frame or client windows.
# example:
#    opacity-rule = [ "80:class_g = 'URxvt'" ];
#
opacity-rule = [
    "00:name = 'bar'",
    "80:name = 'rofi'"
]

#################################
#     Background-Blurring       #
#################################

# Parameters for background blurring, see the *BLUR* section for more information.
blur-method = "gaussian"
blur-size = 20
blur-deviation = 10.0

# Blur background of semi-transparent / ARGB windows.
# Bad in performance, with driver-dependent behavior.
# The name of the switch may change without prior notifications.
#
blur-background = true

# Blur background of windows when the window frame is not opaque.
# Implies:
#    blur-background
# Bad in performance, with driver-dependent behavior. The name may change.
#
# blur-background-frame = false

# Use fixed blur strength rather than adjusting according to window opacity.
# blur-background-fixed = false

# Specify the blur convolution kernel, with the following format:
# example:
#   blur-kern = "5,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1";
#
# blur-kern = ''
blur-kern = "7x7box"

# Exclude conditions for background blur.
# blur-background-exclude = []
blur-background-exclude = [
  "window_type = 'dock'",
  "window_type = 'desktop'",
  "_GTK_FRAME_EXTENTS@:c"
]

#################################
#       General Settings        #
#################################

# Daemonize process. Fork to background after initialization. Causes issues with certain (badly-written) drivers.
daemon = false

# Specify the backend to use: `xrender`, `glx`, or `xr_glx_hybrid`.
# `xrender` is the default one.
# glx works better usually, xrender seems to work better with nvidia

backend = "glx"

# Enable/disable VSync.
vsync = true

# Enable remote control via D-Bus. See the *D-BUS API* section below for more details.
# dbus = false

# Try to detect WM windows (a non-override-redirect window with no
# child that has 'WM_STATE') and mark them as active.
#
# mark-wmwin-focused = false
mark-wmwin-focused = true

# Mark override-redirect windows that doesn't have a child window with 'WM_STATE' focused.
# mark-ovredir-focused = false
mark-ovredir-focused = true

# Try to detect windows with rounded corners and don't consider them
# shaped windows. The accuracy is not very high, unfortunately.
#
# detect-rounded-corners = false
detect-rounded-corners = false

# Detect '_NET_WM_OPACITY' on client windows, useful for window managers
# not passing '_NET_WM_OPACITY' of client windows to frame windows.
#
# detect-client-opacity = false
detect-client-opacity = true

# Specify refresh rate of the screen. If not specified or 0, picom will
# try detecting this with X RandR extension.
#
# refresh-rate = 60
refresh-rate = 0

# Limit picom to repaint at most once every 1 / 'refresh_rate' second to
# boost performance. This should not be used with
#   vsync drm/opengl/opengl-oml
# as they essentially does sw-opti's job already,
# unless you wish to specify a lower refresh rate than the actual value.
#
# sw-opti =

# Use EWMH '_NET_ACTIVE_WINDOW' to determine currently focused window,
# rather than listening to 'FocusIn'/'FocusOut' event. Might have more accuracy,
# provided that the WM supports it.
#
# use-ewmh-active-win = false

# Unredirect all windows if a full-screen opaque window is detected,
# to maximize performance for full-screen windows. Known to cause flickering
# when redirecting/unredirecting windows.
#
unredir-if-possible = true

# Delay before unredirecting the window, in milliseconds. Defaults to 0.
# unredir-if-possible-delay = 0

# Conditions of windows that shouldn't be considered full-screen for unredirecting screen.
# unredir-if-possible-exclude = []

# Use 'WM_TRANSIENT_FOR' to group windows, and consider windows
# in the same group focused at the same time.
#
# detect-transient = false
detect-transient = true

# Use 'WM_CLIENT_LEADER' to group windows, and consider windows in the same
# group focused at the same time. 'WM_TRANSIENT_FOR' has higher priority if
# detect-transient is enabled, too.
#
# detect-client-leader = false
detect-client-leader = true

# Resize damaged region by a specific number of pixels.
# A positive value enlarges it while a negative one shrinks it.
# If the value is positive, those additional pixels will not be actually painted
# to screen, only used in blur calculation, and such. (Due to technical limitations,
# with use-damage, those pixels will still be incorrectly painted to screen.)
# Primarily used to fix the line corruption issues of blur,
# in which case you should use the blur radius value here
# (e.g. with a 3x3 kernel, you should use `--resize-damage 1`,
# with a 5x5 one you use `--resize-damage 2`, and so on).
# May or may not work with *--glx-no-stencil*. Shrinking doesn't function correctly.
#
# resize-damage = 1

# Specify a list of conditions of windows that should be painted with inverted color.
# Resource-hogging, and is not well tested.
#
# invert-color-include = []

# GLX backend: Avoid using stencil buffer, useful if you don't have a stencil buffer.
# Might cause incorrect opacity when rendering transparent content (but never
# practically happened) and may not work with blur-background.
# My tests show a 15% performance boost. Recommended.
#
#glx-no-stencil = true

# GLX backend: Avoid rebinding pixmap on window damage.
# Probably could improve performance on rapid window content changes,
# but is known to break things on some drivers (LLVMpipe, xf86-video-intel, etc.).
# Recommended if it works.
#
glx-no-rebind-pixmap = true

# Disable the use of damage information.
# This cause the whole screen to be redrawn everytime, instead of the part of the screen
# has actually changed. Potentially degrades the performance, but might fix some artifacts.
# The opposing option is use-damage
#
# no-use-damage = false
use-damage = true

# Use X Sync fence to sync clients' draw calls, to make sure all draw
# calls are finished before picom starts drawing. Needed on nvidia-drivers
# with GLX backend for some users.
#
xrender-sync-fence = true

# GLX backend: Use specified GLSL fragment shader for rendering window contents.
# See `compton-default-fshader-win.glsl` and `compton-fake-transparency-fshader-win.glsl`
# in the source tree for examples.
#
# glx-fshader-win = ''

# Force all windows to be painted with blending. Useful if you
# have a glx-fshader-win that could turn opaque pixels transparent.
#
# force-win-blend = false

# Do not use EWMH to detect fullscreen windows.
# Reverts to checking if a window is fullscreen based only on its size and coordinates.
#
# no-ewmh-fullscreen = false

# Dimming bright windows so their brightness doesn't exceed this set value.
# Brightness of a window is estimated by averaging all pixels in the window,
# so this could comes with a performance hit.
# Setting this to 1.0 disables this behaviour. Requires --use-damage to be disabled. (default: 1.0)
#
# max-brightness = 1.0

# Make transparent windows clip other windows like non-transparent windows do,
# instead of blending on top of them.
#
# transparent-clipping = false

# Set the log level. Possible values are:
#  "trace", "debug", "info", "warn", "error"
# in increasing level of importance. Case doesn't matter.
# If using the "TRACE" log level, it's better to log into a file
# using *--log-file*, since it can generate a huge stream of logs.
#
# log-level = "debug"
log-level = "warn";

# Set the log file.
# If *--log-file* is never specified, logs will be written to stderr.
# Otherwise, logs will to written to the given file, though some of the early
# logs might still be written to the stderr.
# When setting this option from the config file, it is recommended to use an absolute path.
#
# log-file = '/path/to/your/log/file'

# Show all X errors (for debugging)
# show-all-xerrors = false

# Write process ID to a file.
# write-pid-path = '/path/to/your/log/file'

# Window type settings
#
# 'WINDOW_TYPE' is one of the 15 window types defined in EWMH standard:
#     "unknown", "desktop", "dock", "toolbar", "menu", "utility",
#     "splash", "dialog", "normal", "dropdown_menu", "popup_menu",
#     "tooltip", "notification", "combo", and "dnd".
#
# Following per window-type options are available: ::
#
#   fade, shadow:::
#     Controls window-type-specific shadow and fade settings.
#
#   opacity:::
#     Controls default opacity of the window type.
#
#   focus:::
#     Controls whether the window of this type is to be always considered focused.
#     (By default, all window types except "normal" and "dialog" has this on.)
#
#   full-shadow:::
#     Controls whether shadow is drawn under the parts of the window that you
#     normally won't be able to see. Useful when the window has parts of it
#     transparent, and you want shadows in those areas.
#
#   redir-ignore:::
#     Controls whether this type of windows should cause screen to become
#     redirected again after been unredirected. If you have unredir-if-possible
#     set, and doesn't want certain window to cause unnecessary screen redirection,
#     you can set this to `true`.
#
wintypes:
{
  tooltip = { fade = true; shadow = true; opacity = 0.75; focus = true; full-shadow = false; };
  dock = { shadow = false; }
  dnd = { shadow = false; }
  popup_menu = { opacity = 0.8; }
  dropdown_menu = { opacity = 0.8; }
};

Steps of reproduction

Get lemonbar from here.. I haven't tried reproducing this with any other software.
Add a line in picom.conf setting opacity to 0 if wm_name is bar.
Run echo "hi" | lemonbar -g "50x50+500+500" -d -p

Expected behavior

The bar should not be visible on any workspace.

Current Behavior

It is not visible when there are >= 2 windows already existing in that workspace.
It is not visible if you are on step 1 and move to a workspace that has no existing windows.
It is visible if there is only one window in the workspace.
It vanishes if you add another window to the workspace from step 3.
It is visible if you are on step 3 and move to a workspace that has no existing windows.

yshui / picom

Picom transparency not working on workspaces with only one window #452

Platform

GPU, drivers, and screen setup

Environment

picom version

Configuration:

Steps of reproduction

Expected behavior

Current Behavior