wezterm: add DisableDefaultAssignment action

Similar to Nop but allows the key press to pass through to
the underlying tab.

Expand docs to clarify how these two actions work.

docs/config/keys.markdown

@@ -415,16 +415,32 @@ return {
 }
 ```
 
-## Nop
+## DisableDefaultAssignment
 
-Does nothing.  This is useful to disable a default key assignment.
+Has no special meaning of its own; this action will undo the registration
+of a default assignment if that key/mouse/modifier combination is one of the
+default assignments and cause the key press to be propagated through
+to the tab for processing.
 
 ```lua
-local wezterm = require 'wezterm';
-
 return {
   keys = {
-    -- Turn off the default CMD-m Hide action
+    -- Turn off the default CMD-m Hide action, allowing CMD-m to
+    -- be potentially recognized and handled by the tab
+    {key="m", mods="CMD", action="DisableDefaultAssignment"},
+  }
+}
+```
+
+## Nop
+
+Causes the key press to have no effect; it behaves as though those
+keys were not pressed.
+
+```lua
+return {
+  keys = {
+    -- Turn off any side effects from pressing CMD-m
     {key="m", mods="CMD", action="Nop"},
   }
 }

src/frontend/gui/termwindow.rs

@@ -1444,7 +1444,7 @@ impl TermWindow {
                 }
             }
             CloseCurrentTab => self.close_current_tab(),
-            Nop => {}
+            Nop | DisableDefaultAssignment => {}
             ReloadConfiguration => crate::config::reload(),
             MoveTab(n) => self.move_tab(*n)?,
             MoveTabRelative(n) => self.move_tab_relative(*n)?,

src/keyassignment.rs

@@ -24,7 +24,7 @@ pub enum MouseEventTrigger {
 
 /// When spawning a tab, specify which domain should be used to
 /// host/spawn that tab.
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq)]
 pub enum SpawnTabDomain {
     /// Use the default domain
     DefaultDomain,
@@ -42,7 +42,7 @@ impl Default for SpawnTabDomain {
     }
 }
 
-#[derive(Default, Debug, Clone, Deserialize, Serialize)]
+#[derive(Default, Debug, Clone, Deserialize, Serialize, PartialEq, Eq)]
 pub struct SpawnCommand {
     /// Optional descriptive label
     pub label: Option<String>,
@@ -70,7 +70,7 @@ pub struct SpawnCommand {
     pub domain: SpawnTabDomain,
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq)]
 pub enum KeyAssignment {
     SpawnTab(SpawnTabDomain),
     SpawnWindow,
@@ -85,6 +85,7 @@ pub enum KeyAssignment {
     ActivateTab(usize),
     SendString(String),
     Nop,
+    DisableDefaultAssignment,
     Hide,
     Show,
     CloseCurrentTab,
@@ -343,6 +344,9 @@ impl InputMap {
             );
         }
 
+        keys.retain(|_, v| *v != KeyAssignment::DisableDefaultAssignment);
+        mouse.retain(|_, v| *v != KeyAssignment::DisableDefaultAssignment);
+
         Self { keys, mouse }
     }
 

src/mux/tab.rs

@@ -45,7 +45,7 @@ fn schedule_next_paste(paste: &Arc<Mutex<Paste>>) {
     });
 }
 
-#[derive(Debug, Clone, Deserialize, Serialize)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq)]
 pub enum Pattern {
     CaseSensitiveString(String),
     CaseInSensitiveString(String),