From 312c3f0d46ee749b2e4f4b918ff26c082a4b7445 Mon Sep 17 00:00:00 2001
From: zwim <36999612+zwim@users.noreply.github.com>
Date: Sat, 12 Oct 2024 21:06:30 +0200
Subject: [PATCH] Terminal: Move some boilerplate setup code outside of the
 child shell process

Salvaged from @zwim's original code in #12384
---
 plugins/terminal.koplugin/main.lua | 64 +++++++++++++++++-------------
 1 file changed, 37 insertions(+), 27 deletions(-)

diff --git a/plugins/terminal.koplugin/main.lua b/plugins/terminal.koplugin/main.lua
index ec9647258..4b1dcbcac 100644
--- a/plugins/terminal.koplugin/main.lua
+++ b/plugins/terminal.koplugin/main.lua
@@ -106,6 +106,7 @@ function Terminal:getDefaultShellExecutable()
         "sh",
         "dash",
         "ash",
+        "hush",
         "zsh",
         "ksh",
         "mksh",
@@ -161,7 +162,7 @@ function Terminal:spawnShell(cols, rows)
         return false
     end
     if C.unlockpt(self.ptmx) ~= 0 then
-        logger.err("Terminal: can not unockpt:", ffi.string(C.strerror(ffi.errno())))
+        logger.err("Terminal: can not unlockpt:", ffi.string(C.strerror(ffi.errno())))
         C.close(self.ptmx)
         return false
     end
@@ -177,6 +178,29 @@ function Terminal:spawnShell(cols, rows)
 
     logger.dbg("Terminal: slave_pty", self.slave_pty)
 
+    -- Prepare shell call
+    local function get_readline_wrapper()
+        if self:isExecutable("rlfe") then
+            return "rlfe"
+        elseif self:isExecutable("rlwrap") then
+            return "rlwrap"
+        end
+    end
+    local profile_file = "./plugins/terminal.koplugin/profile"
+    local rlw = get_readline_wrapper()
+    local shell = G_reader_settings:readSetting("terminal_shell")
+    local args = {}
+    if shell:find("bash") then
+        args = { "--rcfile", profile_file}
+    end
+
+    if not self:isExecutable(shell) then
+        UIManager:show(InfoMessage:new{
+            text = _("Shell is not executable"),
+        })
+        return false
+    end
+
     local pid = C.fork()
     if pid < 0 then
         logger.err("Terminal: fork failed:", ffi.string(C.strerror(ffi.errno())))
@@ -209,7 +233,6 @@ function Terminal:spawnShell(cols, rows)
             end
         end
 
-        local profile_file = "./plugins/terminal.koplugin/profile"
         C.setenv("TERM", "vt52", 1)
         C.setenv("ENV", profile_file, 1) -- when bash is started as sh
         C.setenv("BASH_ENV", profile_file, 1) -- when bash is started non-interactive
@@ -218,27 +241,8 @@ function Terminal:spawnShell(cols, rows)
             C.setenv("ANDROID", "ANDROID", 1)
         end
 
-        local function get_readline_wrapper()
-            if self:isExecutable("rlfe") then
-                return "rlfe"
-            elseif self:isExecutable("rlwrap") then
-                return "rlwrap"
-            else
-                return
-            end
-        end
-
-        -- Here we use an existing readline wrapper
-        local rlw = get_readline_wrapper()
-        local shell = G_reader_settings:readSetting("terminal_shell")
-
-        local args = {}
-        if shell:find("bash") then
-            args = { "--rcfile", profile_file}
-        end
-
-        if not self:isExecutable(shell)
-            or (rlw and C.execlp(rlw, rlw, shell, unpack(args)) ~= 0)
+        -- Here we attempt to use an existing readline wrapper
+        if (rlw and C.execlp(rlw, rlw, shell, unpack(args)) ~= 0)
             or C.execlp(shell, shell, unpack(args)) ~= 0 then
 
             -- the following two prints are shown in the terminal emulator.
@@ -658,10 +662,16 @@ Aliases (shortcuts) to frequently used commands can be placed in:
                                     if new_shell == "" then
                                         new_shell = "sh"
                                     end
-                                    G_reader_settings:saveSetting("terminal_shell", new_shell)
-                                    UIManager:close(self.shell_dialog)
-                                    if touchmenu_instance then
-                                        touchmenu_instance:updateItems()
+                                    if self:isExecutable(new_shell) then
+                                        G_reader_settings:saveSetting("terminal_shell", new_shell)
+                                        UIManager:close(self.shell_dialog)
+                                        if touchmenu_instance then
+                                            touchmenu_instance:updateItems()
+                                        end
+                                    else
+                                        UIManager:show(InfoMessage:new{
+                                            text = _("Shell is not executable"),
+                                        })
                                     end
                                 end
                             },