Fix hang when returning from shell command (#4126)

- **PR Description**

In #3793 we changed the execution of shell commands to use an
interactive shell (-i), because this allows users to use aliases or
shell functions, which is a nice convenience.

Since then, however, many users have reported problems with lazygit not
coming back to the foreground after executing a shell command. Some
users report that appending "; exit" to the end of the command line
solves this. I don't really understand what the cause of this problem
was, or why appending "; exit" solves it, but if it helps, let's do it.

Fixes #3903, #3923, #3937.

- **Please check if the PR fulfills these requirements**

* [x] Cheatsheets are up-to-date (run `go generate ./...`)
* [x] Code has been formatted (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#code-formatting))
* [ ] Tests have been added/updated (see
[here](https://github.com/jesseduffield/lazygit/blob/master/pkg/integration/README.md)
for the integration test guide)
* [ ] Text is internationalised (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#internationalisation))
* [ ] If a new UserConfig entry was added, make sure it can be
hot-reloaded (see
[here](https://github.com/jesseduffield/lazygit/blob/master/docs/dev/Codebase_Guide.md#using-userconfig))
* [ ] Docs have been updated if necessary
* [x] You've read through your own file changes for silly mistakes etc

pkg/commands/oscommands/cmd_obj_builder.go

@@ -52,7 +52,7 @@ func (self *CmdObjBuilder) NewShell(commandStr string) ICmdObj {
 }
 
 func (self *CmdObjBuilder) NewInteractiveShell(commandStr string) ICmdObj {
-	quotedCommand := self.quotedCommandString(commandStr)
+	quotedCommand := self.quotedCommandString(commandStr + self.platform.InteractiveShellExit)
 	cmdArgs := str.ToArgv(fmt.Sprintf("%s %s %s %s", self.platform.InteractiveShell, self.platform.InteractiveShellArg, self.platform.ShellArg, quotedCommand))
 
 	return self.New(cmdArgs)

pkg/commands/oscommands/dummies.go

@@ -56,6 +56,7 @@ var dummyPlatform = &Platform{
 	InteractiveShell:     "bash",
 	ShellArg:             "-c",
 	InteractiveShellArg:  "-i",
+	InteractiveShellExit: "; exit $?",
 	OpenCommand:          "open {{filename}}",
 	OpenLinkCommand:      "open {{link}}",
 }

pkg/commands/oscommands/os.go

@@ -40,6 +40,7 @@ type Platform struct {
 	InteractiveShell     string
 	ShellArg             string
 	InteractiveShellArg  string
+	InteractiveShellExit string
 	OpenCommand          string
 	OpenLinkCommand      string
 }

pkg/commands/oscommands/os_default_platform.go

@@ -15,6 +15,7 @@ func GetPlatform() *Platform {
 		InteractiveShell:     getUserShell(),
 		ShellArg:             "-c",
 		InteractiveShellArg:  "-i",
+		InteractiveShellExit: "; exit $?",
 		OpenCommand:          "open {{filename}}",
 		OpenLinkCommand:      "open {{link}}",
 	}

pkg/commands/oscommands/os_windows.go

@@ -7,5 +7,6 @@ func GetPlatform() *Platform {
 		InteractiveShell:     "cmd",
 		ShellArg:             "/c",
 		InteractiveShellArg:  "",
+		InteractiveShellExit: "",
 	}
 }