translate-c: Function-local extern variable is missing namespace qualifier

[linusg]

Zig Version

0.14.0-dev.577+3344ed8b8

Steps to Reproduce and Observed Behavior

static inline CFNT_s* fontGetSystemFont(void)
{
	extern CFNT_s* g_sharedFont;
	if (!g_sharedFont)
		fontEnsureMapped();
	return g_sharedFont;
}

(https://github.com/devkitPro/libctru/blob/faf5162b60eab5402d3839330f985b84382df76c/libctru/include/3ds/font.h#L168-L174)

gets translated as

pub fn fontGetSystemFont() callconv(.C) [*c]CFNT_s {
    const ExternLocal_g_sharedFont = struct {
        extern var g_sharedFont: [*c]CFNT_s;
    };
    _ = &ExternLocal_g_sharedFont;
    if (!(g_sharedFont != null)) {
        _ = fontEnsureMapped();
    }
    return ExternLocal_g_sharedFont.g_sharedFont;
}

which doesn't build:

error: use of undeclared identifier 'g_sharedFont'
    if (!(g_sharedFont != null)) {
          ^~~~~~~~~~~~

Expected Behavior

         extern var g_sharedFont: [*c]CFNT_s;
     };
     _ = &ExternLocal_g_sharedFont;
-    if (!(g_sharedFont != null)) {
+    if (!(ExternLocal_g_sharedFont.g_sharedFont != null)) {
         _ = fontEnsureMapped();
     }
     return ExternLocal_g_sharedFont.g_sharedFont;

[linusg]

I suspect this might fix it, but I don't have a local compiler build to test:

--- a/src/translate_c.zig
+++ b/src/translate_c.zig
@@ -1897,7 +1897,7 @@ fn transDeclRefExpr(
     const name = try c.str(@as(*const clang.NamedDecl, @ptrCast(value_decl)).getName_bytes_begin());
     const mangled_name = scope.getAlias(name);
     const decl_is_var = @as(*const clang.Decl, @ptrCast(value_decl)).getKind() == .Var;
-    const potential_local_extern = if (decl_is_var) ((@as(*const clang.VarDecl, @ptrCast(value_decl)).getStorageClass() == .Extern) and (scope.id == .block)) else false;
+    const potential_local_extern = if (decl_is_var) ((@as(*const clang.VarDecl, @ptrCast(value_decl)).getStorageClass() == .Extern) and (scope.id != .root)) else false;
 
     var confirmed_local_extern = false;
     var ref_expr = val: {