Fix issue 24632 - Fully qualified package name in package requires import

checkAccess(Scope*, Package) only treated a package as self-accessible
when sc._module == p. When the fully qualified reference is to the
enclosing package.d's own name, the resolved symbol is the semantic
Package object, which is a distinct instance from the Module object
for package.d even though p.isPackageMod() == sc._module. That
equality was already checked in the sibling function hasPackageAccess
but missing here, so a package.d module referencing itself by fully
qualified name was wrongly told to add static import.

https://issues.dlang.org/show_bug.cgi?id=24632

Author: usefahmed07

changelog/dmd.package-self-reference.dd

@@ -0,0 +1,18 @@
+Fully qualified self-reference inside `package.d` no longer requires `static import`
+
+Previously, referring to a package's own fully qualified name from
+inside its `package.d` module incorrectly required adding a
+`static import` of itself, even though unqualified access already
+worked without it.
+
+---
+// bug/buggier/package.d
+module bug.buggier;
+
+void fn() {}
+
+void main()
+{
+    bug.buggier.fn(); // used to require `static import bug.buggier;`
+}
+---

compiler/src/dmd/access.d

@@ -228,6 +228,16 @@ bool checkAccess(Scope* sc, Package p)
 {
     if (sc._module == p)
         return false;
+
+    // https://issues.dlang.org/show_bug.cgi?id=24632
+    // A `package.d` module referring to its own fully qualified package
+    // name resolves to the semantic `Package` symbol, not the `Module`
+    // symbol for `package.d` itself, so the check above misses this case.
+    // Treat that as a self-reference too.
+    if (auto m = p.isPackageMod())
+        if (sc._module == m)
+            return false;
+
     for (; sc; sc = sc.enclosing)
     {
         if (sc.scopesym && sc.scopesym.isPackageAccessible(p, Visibility(Visibility.Kind.private_)))

compiler/test/compilable/imports/test20476/bug/buggier/package.d

@@ -0,0 +1,12 @@
+module bug.buggier;
+
+void fn() {}
+
+void self()
+{
+    // https://issues.dlang.org/show_bug.cgi?id=24632
+    // Fully qualifying a package.d module's own name from inside itself
+    // used to require `static import bug.buggier;` -- it shouldn't.
+    alias thisModule = bug.buggier;
+    bug.buggier.fn();
+}

compiler/test/compilable/test20476.d

@@ -0,0 +1,4 @@
+// https://issues.dlang.org/show_bug.cgi?id=24632
+// EXTRA_SOURCES: imports/test20476/bug/buggier/package.d
+
+module test20476;

compiler/test/fail_compilation/fail20476.d

@@ -0,0 +1,10 @@
+// https://issues.dlang.org/show_bug.cgi?id=24632
+// EXTRA_SOURCES: imports/fail20476/bug/buggier/package.d imports/fail20476/bug/other/package.d
+/*
+TEST_OUTPUT:
+---
+fail_compilation/imports/fail20476/bug/other/package.d(3): Error: undefined identifier `buggier` in package `bug`, perhaps add `static import bug.buggier;`
+---
+*/
+
+module fail20476;

compiler/test/fail_compilation/imports/fail20476/bug/buggier/package.d

@@ -0,0 +1,3 @@
+module bug.buggier;
+
+void pub() {}

compiler/test/fail_compilation/imports/fail20476/bug/other/package.d

@@ -0,0 +1,3 @@
+module bug.other;
+
+void main() { bug.buggier.pub(); }