proper --debug/-D flag support

--debug should not be a global flag, you can only use this as podman
--debug never podman ps --debug. This matches docker and allows us to
add the shorthand "D" since they now no longer conflict.

Fixes changes from commit 2d30b4dee5 which claims to add -D but never
did.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

cmd/podman/root.go

@@ -475,8 +475,8 @@ func rootFlags(cmd *cobra.Command, opts *entities.PodmanConfig) {
 	pFlags.StringVar(&logLevel, logLevelFlagName, logLevel, fmt.Sprintf("Log messages above specified level (%s)", strings.Join(common.LogLevels, ", ")))
 	_ = rootCmd.RegisterFlagCompletionFunc(logLevelFlagName, common.AutocompleteLogLevel)
 
-	pFlags.BoolVar(&debug, "debug", false, "Docker compatibility, force setting of log-level")
-	_ = pFlags.MarkHidden("debug")
+	lFlags.BoolVarP(&debug, "debug", "D", false, "Docker compatibility, force setting of log-level")
+	_ = lFlags.MarkHidden("debug")
 
 	// Only create these flags for ABI connections
 	if !registry.IsRemote() {

test/system/001-basic.bats

@@ -190,7 +190,9 @@ See 'podman version --help'" "podman version --remote"
     run_podman --log-level=error   info
     run_podman --log-level=fatal   info
     run_podman --log-level=panic   info
+    # docker compat
     run_podman --debug   info
+    run_podman -D        info
     run_podman 1 --debug --log-level=panic info
     is "$output" "Setting --log-level and --debug is not allowed"
 }