Fix possible NULL dereference in ExecAlterObjectDependsStmt

alvherre · alvherre · commit bd905a0d0416 · 2016-04-10T11:03:35.000-03:00
I used the wrong variable here.  Doesn't make a difference today because
the only plausible caller passes a non-NULL variable, but someday it
will be wrong, and even today's correctness is subtle: the caller that
does pass a NULL is never invoked because of object type constraints.
Surely not a condition to rely on.

Noted by Coverity
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
@@ -422,7 +422,7 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt *stmt, ObjectAddress *refAddre
 	if (refAddress)
 		*refAddress = refAddr;
 
-	recordDependencyOn(&address, refAddress, DEPENDENCY_AUTO_EXTENSION);
+	recordDependencyOn(&address, &refAddr, DEPENDENCY_AUTO_EXTENSION);
 
 	return address;
 }

Original file line number	Diff line number	Diff line change
`@@ -422,7 +422,7 @@ ExecAlterObjectDependsStmt(AlterObjectDependsStmt stmt, ObjectAddress refAddre`
`422`	`422`	`if (refAddress)`
`423`	`423`	`*refAddress = refAddr;`
`424`	`424`
`425`		`- recordDependencyOn(&address, refAddress, DEPENDENCY_AUTO_EXTENSION);`
	`425`	`+ recordDependencyOn(&address, &refAddr, DEPENDENCY_AUTO_EXTENSION);`
`426`	`426`
`427`	`427`	`return address;`
`428`	`428`	`}`