Understanding internal variable scope

[Robert E. Griffith]

I would like to understand better the internal variable scopes in the 
bash source code. Do you know of any documentation or past emails I can 
read on it? I am pretty familiar with the code now but I think I have 
some misconceptions because sometimes functions do not act like I 
expect. Maybe the temporary scope is not quite like I think it is.

In particular, I have two issues that I dont understand.

1) I find that when my loadable builtin is called from a bash function, 
sometimes the following code works to create a local variable in the 
calling function and sometimes it does not. If I do "local 
myVariableName" before calling the builtin, it always receives hte value.

   bind_variable_value(make_local_variable("myVariableName",0), "SomeValue..., 
0)

2) There seems to be a difference between sourcing a script at global 
scope as opposed to sourcing it from inside a bash function but I cant 
quite pin it down. Sometimes variables declared in the global scope 
"declare <myvar>" of a sourced script do not exist after sourcing the 
script but functions from the script always do.

--BobG