Fix Issue 20130 - ICE when casting from string to other array type du…

src/dmd/expressionsem.d

@@ -7076,8 +7076,8 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
                 auto tFrom = t1b.nextOf();
                 auto tTo = tob.nextOf();
 
-                // https://issues.dlang.org/show_bug.cgi?id=19954
-                if (exp.e1.op != TOK.string_ || tTo.ty == Tarray)
+                // https://issues.dlang.org/show_bug.cgi?id=20130
+                if (exp.e1.op != TOK.string_ || !ex.isStringExp)
                 {
                     const uint fromSize = cast(uint)tFrom.size();
                     const uint toSize = cast(uint)tTo.size();

test/runnable/test20130.d

@@ -0,0 +1,44 @@
+// https://issues.dlang.org/show_bug.cgi?id=20130
+
+void main() {
+    auto a1 = cast(char[])  "12345678";
+    auto a2 = cast(wchar[]) "12345678"; // Or cast(string|wstring|dstring).
+    auto a3 = cast(dchar[]) "12345678"; // Encoding conversion.
+    assert(a1.length == 8);
+    assert(a2.length == 8);
+    assert(a3.length == 8);
+
+    auto b1 = cast(char[])  "12345678"c;
+    auto b2 = cast(wchar[]) "12345678"c;
+    auto b3 = cast(dchar[]) "12345678"c;
+    assert(b1.length == 8);
+    assert(b2.length == 4);
+    assert(b3.length == 2);
+
+    auto c1 = cast(char[])  "12345678"w;
+    auto c2 = cast(wchar[]) "12345678"w;
+    auto c3 = cast(dchar[]) "12345678"w;
+    assert(c1.length == 16);
+    assert(c2.length == 8);
+    assert(c3.length == 4);
+
+    auto d1 = cast(char[])  "12345678"d;
+    auto d2 = cast(wchar[]) "12345678"d;
+    auto d3 = cast(dchar[]) "12345678"d;
+    assert(d1.length == 32);
+    assert(d2.length == 16);
+    assert(d3.length == 8);
+
+    auto a = cast(uint[]) "12345678";
+    auto b = cast(uint[]) "12345678"d;
+    auto c = cast(uint[]) "12345678"w;
+    auto d = cast(const char[5][]) "12345";
+    auto e = cast(const wchar[2][]) "12345678";
+    immutable f = cast(immutable(uint)[]) "123456789012";
+    assert(a.length == 2);
+    assert(b.length == 8);
+    assert(c.length == 4);
+    assert(d.length == 1);
+    assert(e.length == 2);
+    assert(f.length == 3);
+}