From 2b986821b8f8f32436df5608294382cc0a14256f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jarno=20M=C3=A4kip=C3=A4=C3=A4?= <jmakip87@gmail.com>
Date: Fri, 3 Feb 2023 20:08:42 +0200
Subject: [PATCH] vi: fix regression on wq, add modified() subroutine

Replaced TT.modified with function that checks if buffer has changed.

Fix problems with empty file, by adding LF on load.
(when checking output this is behavior most other editors do)
---
 toys/pending/vi.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/toys/pending/vi.c b/toys/pending/vi.c
index 77a031ba..30a6e03b 100644
--- a/toys/pending/vi.c
+++ b/toys/pending/vi.c
@@ -42,8 +42,6 @@ GLOBALS(
     char* data;
   } yank;
 
-  int modified; // TODO: no editing operations actually set this!
-
   size_t filesize;
 // mem_block contains RO data that is either original file as mmap
 // or heap allocated inserted data
@@ -292,6 +290,17 @@ static int cut_str(size_t offset, size_t len)
 
   return 0;
 }
+static int modified()
+{
+  if (TT.text->next !=  TT.text->prev) return 1;
+  if (TT.slices->next != TT.slices->prev) return 1;
+  if (!TT.text || !TT.slices) return 0;
+  if (!TT.text->node || !TT.slices->node) return 0;
+  if (TT.text->node->alloc != MMAP) return 1;
+  if (TT.text->node->len != TT.slices->node->len) return 1;
+  if (!TT.text->node->len) return 1;
+  return 0;
+}
 
 //find offset position in slices
 static struct slice_list *slice_offset(size_t *start, size_t offset)
@@ -538,6 +547,7 @@ static void linelist_load(char *filename, int ignore_missing)
   if (!filename) filename = TT.filename;
   if (!filename) {
     // `vi` with no arguments creates a new unnamed file.
+    insert_str(xstrdup("\n"), 0, 1, 1, HEAP);
     return;
   }
 
@@ -547,6 +557,7 @@ static void linelist_load(char *filename, int ignore_missing)
       show_error("Couldn't open \"%s\" for reading: %s", filename,
           strerror(errno));
     }
+    insert_str(xstrdup("\n"), 0, 1, 1, HEAP);
     return;
   }
 
@@ -554,6 +565,8 @@ static void linelist_load(char *filename, int ignore_missing)
   if (size > 0) {
     insert_str(xmmap(0,size,PROT_READ,MAP_SHARED,fd,0), 0, size, size, MMAP);
     TT.filesize = text_filesize();
+  } else if (!size) {
+    insert_str(xstrdup("\n"), 0, 1, 1, HEAP);
   }
   xclose(fd);
 }
@@ -563,6 +576,9 @@ static int write_file(char *filename)
   struct slice_list *s = TT.slices;
   struct stat st;
   int fd = 0;
+  if (!modified()) {
+    show_error("Not modified");
+  }
 
   if (!filename) filename = TT.filename;
   if (!filename) {
@@ -1309,13 +1325,14 @@ static int run_ex_cmd(char *cmd)
     // TODO: backwards search.
   } else if (cmd[0] == ':') {
     if (!strcmp(&cmd[1], "q") || !strcmp(&cmd[1], "q!")) {
-      if (cmd[2] != '!' && TT.modified) {
+      if (cmd[2] != '!' && modified()) {
         show_error("Unsaved changes (\"q!\" to ignore)");
       } else return 1;
     } else if (strstr(&cmd[1], "w ")) {
       write_file(&cmd[3]);
     } else if (strstr(&cmd[1], "wq")) {
-      return write_file(0);
+      if (!write_file(0)) return 1;
+      show_error("Unsaved changes (\"q!\" to ignore)");
     } else if (strstr(&cmd[1], "w")) {
       write_file(0);
     } else if (strstr(&cmd[1], "set list")) {
-- 
2.39.2