From 86c1aed20d3900b2a5df905a821bf13a074dc102 Mon Sep 17 00:00:00 2001
From: Kelly Wilson <wilsonk@cpsc.ucalgary.ca>
Date: Sun, 25 Apr 2021 23:26:12 -0600
Subject: [PATCH 1/2] Fix for issue 820 (import name is not an identifier)

---
 src/checker.cpp | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/checker.cpp b/src/checker.cpp
index f386d6da7..42462c0fa 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -3747,6 +3747,19 @@ Array<ImportPathItem> find_import_path(Checker *c, AstPackage *start, AstPackage
 	return empty_path;
 }
 #endif
+
+String get_invalid_import_name(String input) {
+	isize slash = 0;
+	for (isize i = input.len-1; i >= 0; i--) {
+		if (input[i] == '/' || input[i] == '\\') {
+			break;
+		}
+		slash = i;
+	}
+	input = substring(input, slash, input.len);
+	return input;
+}
+
 void check_add_import_decl(CheckerContext *ctx, Ast *decl) {
 	if (decl->state_flags & StateFlag_BeenHandled) return;
 	decl->state_flags |= StateFlag_BeenHandled;
@@ -3804,7 +3817,14 @@ void check_add_import_decl(CheckerContext *ctx, Ast *decl) {
 		if (id->is_using) {
 			// TODO(bill): Should this be a warning?
 		} else {
-			error(token, "Import name, %.*s, cannot be use as an import name as it is not a valid identifier", LIT(id->import_name.string));
+			if (id->import_name.string == "") {
+				String invalid_name = id->fullpath;
+				invalid_name = get_invalid_import_name(invalid_name);
+
+				error(id->token, "Import name %.*s, is not a valid identifier. Perhaps you want to reference the package by a different name like this: import <new_name> \"%.*s\" ", LIT(invalid_name), LIT(invalid_name));
+			} else {
+				error(token, "Import name, %.*s, cannot be use as an import name as it is not a valid identifier", LIT(id->import_name.string));
+			}
 		}
 	} else {
 		GB_ASSERT(id->import_name.pos.line != 0);

From aa846d0ea5f40361cc4ada2213c4659fe1b59580 Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Mon, 26 Apr 2021 11:46:26 +0100
Subject: [PATCH 2/2] Fix `union #maybe` comparison against `nil` -llvm-api

---
 src/llvm_backend.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp
index 0d27b9c6f..a92f53774 100644
--- a/src/llvm_backend.cpp
+++ b/src/llvm_backend.cpp
@@ -10118,6 +10118,9 @@ lbValue lb_emit_comp_against_nil(lbProcedure *p, TokenKind op_kind, lbValue x) {
 			} else if (op_kind == Token_NotEq) {
 				return lb_const_bool(p->module, t_llvm_bool, false);
 			}
+		} else if (is_type_union_maybe_pointer(t)) {
+			lbValue tag = lb_emit_transmute(p, x, t_rawptr);
+			return lb_emit_comp_against_nil(p, op_kind, tag);
 		} else {
 			lbValue tag = lb_emit_union_tag_value(p, x);
 			return lb_emit_comp(p, op_kind, tag, lb_zero(p->module, tag.type));