Re: in-catalog Extension Scripts and Control parameters (templates?)

I think this is unlikely to work reliably:

+ PG_TRY();
+ {
+ ExtensionControl *control = read_extension_control_file(extname);
+
+ if (control)
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("extension \"%s\" is already available", extname)));
+ }
+ }
+ PG_CATCH();
+ {
+ /* no control file found is good news for us */
+ }
+ PG_END_TRY();

What if read_extension_control_file() fails because of an out-of-memory
error? I think you need to extend that function to have a more useful
API, not rely on it raising a specific error. There is at least one
more case when you're calling that function in the same way.

It'd probably work to have a boolean return (found/not found), and
return the ExtensionControl structure through a pointer.

--
Álvaro Herrera http://www.2ndQuadrant.com/
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