From 985e85cc56cd8099a04b46bf0e5a2d2ca521e862 Mon Sep 17 00:00:00 2001
From: Kartik Agaram <vc@akkartik.com>
Date: Wed, 16 Sep 2020 09:36:38 -0700
Subject: 6788

---
 306files.subx       |  3 +++
 apps/browse/main.mu | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/306files.subx b/306files.subx
index bbeece76..f547e8e1 100644
--- a/306files.subx
+++ b/306files.subx
@@ -44,6 +44,9 @@ open:  # filename: (addr array byte), write?: boolean, out: (addr handle buffere
     89/<- %ecx 0/r32/eax
     # restore edx
     5a/pop-to-edx
+    # if fd < 0 return
+    3d/compare-eax-with 0/imm32
+    7c/jump-if-< $open:end/disp8
     # allocate a buffered-file
     (allocate Heap 0x1010 *(ebp+0x10))  # file-buffer-size + 16 for other fields
     # var out-addr/edi: (addr buffered-file)
diff --git a/apps/browse/main.mu b/apps/browse/main.mu
index dca84559..3736c1f4 100644
--- a/apps/browse/main.mu
+++ b/apps/browse/main.mu
@@ -27,6 +27,7 @@ fn main args-on-stack: (addr array addr array byte) -> exit-status/ebx: int {
 }
 
 fn interactive args: (addr array addr array byte) -> exit-status/ebx: int {
+$interactive:body: {
   # initialize fs from args[1]
   var filename/eax: (addr array byte) <- first-arg args
   var file-storage: (handle buffered-file)
@@ -34,6 +35,14 @@ fn interactive args: (addr array addr array byte) -> exit-status/ebx: int {
   open filename, 0, file-storage-addr
   var _fs/eax: (addr buffered-file) <- lookup file-storage
   var fs/esi: (addr buffered-file) <- copy _fs
+  # if no file, exit
+  {
+    compare fs, 0
+    break-if-!=
+    print-string-to-real-screen "file not found\n"
+    exit-status <- copy 1
+    break $interactive:body
+  }
   #
   enable-screen-grid-mode
   enable-keyboard-immediate-mode
@@ -53,6 +62,7 @@ fn interactive args: (addr array addr array byte) -> exit-status/ebx: int {
   enable-screen-type-mode
   exit-status <- copy 0
 }
+}
 
 fn render screen: (addr paginated-screen), fs: (addr buffered-file) {
   start-drawing screen
-- 
cgit 1.4.1-2-gfad0