add canonicalize_pasted_newlines config option

refs: #1213

config/src/lib.rs

@@ -1237,9 +1237,16 @@ pub struct Config {
 
     #[serde(default)]
     pub audible_bell: AudibleBell,
+
+    #[serde(default = "default_canonicalize_pasted_newlines")]
+    pub canonicalize_pasted_newlines: bool,
 }
 impl_lua_conversion!(Config);
 
+fn default_canonicalize_pasted_newlines() -> bool {
+    cfg!(windows)
+}
+
 fn default_mux_env_remove() -> Vec<String> {
     vec![
         "SSH_AUTH_SOCK".to_string(),

config/src/terminal.rs

@@ -70,4 +70,8 @@ impl wezterm_term::TerminalConfiguration for TermConfig {
     fn enable_kitty_graphics(&self) -> bool {
         self.configuration().enable_kitty_graphics
     }
+
+    fn canonicalize_pasted_newlines(&self) -> bool {
+        self.configuration().canonicalize_pasted_newlines
+    }
 }

docs/changelog.md

@@ -25,6 +25,7 @@ As features stabilize some brief notes about them will accumulate here.
 * BSDish systems now support [toast notifications](https://github.com/wez/wezterm/issues/489)
 * [wezterm.background_child_process](config/lua/wezterm/background_child_process.md) function to spawn a process without waiting.
 * [mux_env_remove](config/lua/config/mux_env_remove.md) setting to control which environment variables should be cleared prior to spawning processes in the multiplexer server [#1225](https://github.com/wez/wezterm/issues/1225)
+* [canonicalize_pasted_newlines](config/lua/config/canonicalize_pasted_newlines.md) option to help Windows users manage newlines in pastes [#1213](https://github.com/wez/wezterm/issues/1213)
 
 #### Changed
 

docs/config/lua/config/canonicalize_pasted_newlines.md

@@ -0,0 +1,40 @@
+# canonicalize_pasted_newlines
+
+*Since: nightly builds only*
+
+Controls whether pasted text will have newlines normalized to CRLF form.
+
+In general wezterm tries to stick with unix line endings as the one-true
+representation because using canonical CRLF can result in excess blank lines
+during a paste operation.
+
+On Windows we're in a bit of a frustrating situation: pasting into
+Windows console programs requires CRLF otherwise there is no newline
+at all, but when in WSL, pasting with CRLF gives excess blank lines.
+
+By default, when `canonicalize_pasted_newlines` is not set in your
+configuration, if wezterm is running as a native Windows application, then the
+effective value of this setting will be `true`, otherwise it will be false.
+
+The behavior of this setting is:
+
+* If bracketed paste mode is enabled by the application, this configuration has no effect on the pasted text
+* Otherwise, if `canonicalize_line_endings == true`, then the line endings will be converted to `CRLF` form
+
+In practice, the default setting means that unix shells and vim will get the
+unix newlines in their pastes (which is the UX most users will want) and
+cmd.exe will get CRLF.
+
+However, it is an imperfect world: some users take great pains to only run
+unixy programs from their Windows wezterm, which means that they end up with
+CRLFs in places where they don't want them.  Those users will likely wish to
+set their configuration like this:
+
+```lua
+return {
+  -- I only ever run unix programs, even on my Windows system, so I always
+  -- want my pastes to use unix newlines.
+  canonicalize_pasted_newlines = false,
+}
+```
+

term/src/config.rs

@@ -69,6 +69,10 @@ pub trait TerminalConfiguration: std::fmt::Debug {
         cfg!(windows)
     }
 
+    fn canonicalize_pasted_newlines(&self) -> bool {
+        cfg!(windows)
+    }
+
     fn alternate_buffer_wheel_scroll_speed(&self) -> u8 {
         3
     }

term/src/terminalstate/mod.rs

@@ -644,7 +644,7 @@ impl TerminalState {
 
         // This is a bit horrible; in general we try to stick with unix line
         // endings as the one-true representation because using canonical
-        // CRLF can result is excess blank lines during a paste operation.
+        // CRLF can result in excess blank lines during a paste operation.
         // On Windows we're in a bit of a frustrating situation: pasting into
         // Windows console programs requires CRLF otherwise there is no newline
         // at all, but when in WSL, pasting with CRLF gives excess blank lines.
@@ -657,7 +657,8 @@ impl TerminalState {
         // In practice this means that unix shells and vim will get the
         // unix newlines in their pastes (which is the UX I want) and
         // cmd.exe will get CRLF.
-        let canonicalize_line_endings = cfg!(windows) && !self.bracketed_paste;
+        let canonicalize_line_endings =
+            self.config.canonicalize_pasted_newlines() && !self.bracketed_paste;
 
         if canonicalize_line_endings {
             // Convert (\r|\n) -> \r\n, but not if it is \r\n anyway.