fix minor mem leaks; fix problem with parser state during a DEBUG trap with -T enabled in a shell function; fix crash with propagating array variables; fix overflow in compound array appending

doc/bashref.texi

@@ -6217,6 +6217,7 @@ builtin).
 Setting @code{extdebug} after the shell has started to execute a script,
 or referencing this variable when @code{extdebug} is not set,
 may result in inconsistent values.
+Assignments to @env{BASH_ARGC} have no effect, and it may not be unset.
 
 @item BASH_ARGV
 An array variable containing all of the parameters in the current Bash
@@ -6231,6 +6232,7 @@ builtin).
 Setting @code{extdebug} after the shell has started to execute a script,
 or referencing this variable when @code{extdebug} is not set,
 may result in inconsistent values.
+Assignments to @env{BASH_ARGV} have no effect, and it may not be unset.
 
 @item BASH_ARGV0
 When referenced, this variable expands to the name of the shell or shell
@@ -6295,6 +6297,7 @@ where each corresponding member of @env{FUNCNAME} was invoked.
 @code{$@{FUNCNAME[$i]@}} was called (or @code{$@{BASH_LINENO[$i-1]@}} if
 referenced within another shell function). 
 Use @code{LINENO} to obtain the current line number.
+Assignments to @env{BASH_LINENO} have no effect, and it may not be unset.
 
 @item BASH_LOADABLES_PATH
 A colon-separated list of directories in which the shell looks for
@@ -6324,6 +6327,7 @@ corresponding shell function names in the @code{FUNCNAME} array
 variable are defined.
 The shell function @code{$@{FUNCNAME[$i]@}} is defined in the file
 @code{$@{BASH_SOURCE[$i]@}} and called from @code{$@{BASH_SOURCE[$i+1]@}}
+Assignments to @env{BASH_SOURCE} have no effect, and it may not be unset.
 
 @item BASH_SUBSHELL
 Incremented by one within each subshell or subshell environment when