fix Issue 14560 - Strange -inline behavior

src/inline.c

@@ -506,7 +506,8 @@ Statement *inlineAsStatement(Statement *s, InlineDoState *ids)
         {
             //printf("ReturnStatement::inlineAsStatement() '%s'\n", s->exp ? s->exp->toChars() : "");
             ids->foundReturn = true;
-            result = new ReturnStatement(s->loc, s->exp ? doInline(s->exp, ids) : NULL);
+            if (s->exp) // Bugzilla 14560: 'return' must not leave in the expand result
+                result = new ReturnStatement(s->loc, doInline(s->exp, ids));
         }
 
         void visit(ImportStatement *s)
@@ -1718,6 +1719,11 @@ bool canInline(FuncDeclaration *fd, int hasthis, int hdrscan, int statementsToo)
             (!(fd->hasReturnExp & 1) || statementsToo) &&
             !hdrscan)
             goto Lno;
+
+        /* Bugzilla 14560: If fd returns void, all explicit `return;`s
+         * must not appear in the expanded result.
+         * See also ReturnStatement::inlineAsStatement().
+         */
     }
 
     // cannot inline constructor calls because we need to convert:

test/runnable/inline14560.d

@@ -0,0 +1,17 @@
+// PERMUTE_ARGS: -inline -release -g -O
+
+auto serialize(T)(T value)
+{
+    foreach (i; value) { }
+
+    return;     // important
+    // By this ReturnStatement with NULL exp wrongly appears in the
+    // expanded result of serialize(["test"]) call in main(), it will
+    // return from main() without setting exit code.
+}
+
+int main()
+{
+    serialize(["test"]);
+    return 0;
+}