3884 – Segfault: defining a typedef with an invalid object.d

The following code causes DMD 1.056 to segfault:
typedef int X;
X[] a;
void f() { g(a); }
void g(T...)(T x) {}
Using int[] instead of X[] works.
However, interestingly enough, keeping the typedef but using an int[] also causes a segfault, even though the typedef is unused:
typedef int X;
int[] a;
void f() { g(a); }
void g(T...)(T x) {}

I cannot reproduce the bug on either 1.055 or 1.057 Windows, nor on D2. Is there something missing from the test case?

Took me a while to reproduce it again myself. It's quite different from what I reported: I had an invalid object.d in the working directory, which triggers it. It seems the typedef alone is enough, the array and tuple business is unneeded:
$ cat arst.d
typedef int X;
$ dmd -c arst.d
[no errors]
$ touch object.d
$ dmd -c arst.d 
E: Child terminated by signal ‘Segmentation fault’

This is really obscure, but here's a patch:
typeinf.c, line 108:
Expression *Type::getTypeInfo(Scope *sc)
{
 Expression *e;
 Type *t;
+ if (!Type::typeinfo)
+ {
+	error(0, "TypeInfo not found. object.d may be incorrectly installed or corrupt");
+	return new ErrorExp();
+ }
 //printf("Type::getTypeInfo() %p, %s\n", this, toChars());

changeset 426

Fixed DMD1.058 and 2.043.