Comment #1 by bus_dbugzilla — 2011-03-08T17:50:42Z
Rather, this is *not the same as* issue 5717. They may be related.
Comment #2 by clugdbug — 2011-03-11T04:58:38Z
Like bug 5717, this was caused by the fix to bug 4389 (char[]~dchar and wchar[]~dchar *never* worked).
The problem is in constfold.c, Cat().
It erroneously assumes that all concatenation is equivalent to string ~ dchar. But this isn't true for char[]~char, wchar[]~wchar, (this happens during constant-folding optimization, which is how it manifests in the test case). In such cases the dchar encoding should not occur - it should just give an encoding length of 1, and do a simple memcpy.
It applies to everything of the form (e2->op == TOKint64) in that function.
(1) size_t len = es1->len + utf_codeLength(sz, v);
s = mem.malloc((len + 1) * sz);
memcpy(s, es1->string, es1->len * sz);
(2) utf_encode(sz, (unsigned char *)s + , v);
Lines (1) and (2) are valid for hetero concatenation, but when both types are the same the lines should be:
(1) size_t len = es1->len + 1;
(2) memcpy((unsigned char *)s + (sz * es1->len), &v, sz);
This should definitely be factored out into a helper function -- it's far too repetitive already.