From 43c528652721519dc3f429a264d39059ad816311 Mon Sep 17 00:00:00 2001
From: Derek Stevens <nilix@nilfm.cc>
Date: Thu, 30 Mar 2023 22:33:12 -0600
Subject: [PATCH] taro-ls: fix div by zero when resetting scrollbar; taro-ctl:
 use capped IO to truncate command output before writing message

---
 README.md   |  6 +++---
 taro-ctl.cr | 12 +++++++++++-
 taro-ls.tal |  5 ++++-
 3 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index ed68b5b..d1eb567 100644
--- a/README.md
+++ b/README.md
@@ -19,9 +19,9 @@
 The `config` file is processed into a bunch of constants for `taro-ctl` by the build script. Adjust them to your needs:
 
 - `MBOX_ROOT`: the directory where your maildirs are.
-- `TARO_LIB`: the directory where your runtime files (`taro-ls` rom, `taro-reader` script, `.theme` and `font.icn` files, etc.) will be installed to; probably just where you clone this repo to.
+- `TARO_LIB`: the directory where your runtime files (`taro-ls` rom, `taro-reader` script, `.theme` and `font.icn` files, etc.) will be installed to, as well as a copy of `uxnemu`
 - `TARO_DOWNLOADS`: directory where attachments are downloaded to.
-- `UXN_EMU`: name of the `uxnemu` executable. You can copy `uxnemu` to, eg `taro` and it will have that `_NET_WM_CLASS`.
+- `UXN_EMU`: name the `uxnemu` will be copied to - this is a hack to set the `_NET_WM_CLASS`.
 - `TARO_ENV`: environment variables as you type them in the terminal, that you can use for the `READER_PROG` and `COMPOSE_PROG` commands
 - `READER_PROG`: command to spawn to read mail - by default it calls the `st` terminal with some environment variables and options set, and runs `taro-reader`
 - `COMPOSE_PROG`: command to spawn to write mail - by default it calls the `st` terminal with some environment variables and options set and runs `mcom` from `mblaze`
@@ -126,7 +126,7 @@ Odd messages go from the `uxn` windows to `taro-ctl` (or from `taro-ctl` to itse
 - `9`: trash mail; payload is the beginning and end of the `mmsg` range in u16
 - `11`: read mail; payload is a single u16 `mmsg` number in the current sequence
 - `13`: compose mail; no payload
-- `15`: push view update (keeps search query, for after replying/writing mail or when new mail comes in)
+- `15`: push view update (keeps search query, for after replying/writing mail or when new mail comes in); no payload
 
 ## socket (other IPC)
 
diff --git a/taro-ctl.cr b/taro-ctl.cr
index 7d24e31..7778a39 100644
--- a/taro-ctl.cr
+++ b/taro-ctl.cr
@@ -166,6 +166,16 @@ module Taro
 
   end
   
+  class CappedIO < IO::Memory
+    def write(slice : Bytes)
+      if slice.size >= MSG_SIZES[MsgType::MAIL_LIST]
+        super(slice[0..MSG_SIZES[MsgType::MAIL_LIST] - 1])
+      else
+        super(slice)
+      end
+    end
+  end
+  
   class MblazeProxy
     @@mailbox : String = "INBOX"
     @@search_regex : String = ""
@@ -179,7 +189,7 @@ module Taro
     end
     
     private def run_cmd(cmdtxt : String) : IO::Memory
-      io = IO::Memory.new
+      io = CappedIO.new
       Process.run(cmdtxt, shell: true, output: io)
       return io
     end
diff --git a/taro-ls.tal b/taro-ls.tal
index 3954f99..36cb542 100644
--- a/taro-ls.tal
+++ b/taro-ls.tal
@@ -1118,7 +1118,10 @@ JMP2r
 JMP2r
 
 @update_sb_pos ( list -- )
-
+  DUP SB_STEP LDZ2 #0000 NEQ2 ,&safe_to_divide JCN
+  POP JMP2r
+  
+  &safe_to_divide
   DUP DUP
   LB_TOP LDZ2 ROT SB_STEP LDZ2 DIV2 ROT SB_POS STZ2