From ae65998d5b8080d1304de7c694f90458564f4b12 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Sat, 24 Jan 2026 14:22:25 -0800
Subject: [PATCH] terminal: OSC 133;I

---
 src/terminal/Screen.zig          |  1 +
 src/terminal/Terminal.zig        | 20 ++++++++++++++++++--
 src/terminal/stream_readonly.zig | 16 ++++++++++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/terminal/Screen.zig b/src/terminal/Screen.zig
index 10d33a3a8..e92a81117 100644
--- a/src/terminal/Screen.zig
+++ b/src/terminal/Screen.zig
@@ -137,6 +137,7 @@ pub const Cursor = struct {
     /// The current semantic content type for the cursor that will be
     /// applied to any newly written cells.
     semantic_content: pagepkg.Cell.SemanticContent = .output,
+    semantic_content_clear_eol: bool = false,
 
     /// The pointers into the page list where the cursor is currently
     /// located. This makes it faster to move the cursor.
diff --git a/src/terminal/Terminal.zig b/src/terminal/Terminal.zig
index 0e7cc5d92..2782b8d0e 100644
--- a/src/terminal/Terminal.zig
+++ b/src/terminal/Terminal.zig
@@ -1082,6 +1082,7 @@ pub fn semanticPrompt(
             // the prompt types (k=) because it isn't of value to us
             // currently. This may change in the future.
             self.screens.active.cursor.semantic_content = .prompt;
+            self.screens.active.cursor.semantic_content_clear_eol = false;
 
             // This is a kitty-specific flag that notes that the shell
             // is capable of redraw.
@@ -1114,17 +1115,26 @@ pub fn semanticPrompt(
 
             // As noted above, we don't currently utilize the prompt type.
             self.screens.active.cursor.semantic_content = .prompt;
+            self.screens.active.cursor.semantic_content_clear_eol = false;
         },
 
         .end_prompt_start_input => {
             // End of prompt and start of user input, terminated by a OSC
             // "133;C" or another prompt (OSC "133;P").
             self.screens.active.cursor.semantic_content = .input;
+            self.screens.active.cursor.semantic_content_clear_eol = false;
+        },
+
+        .end_prompt_start_input_terminate_eol => {
+            // End of prompt and start of user input, terminated by end-of-line.
+            self.semanticPromptSet(.input);
+            self.screens.active.cursor.semantic_content_clear_eol = true;
         },
 
         .end_input_start_output => {
             // "End of input, and start of output."
             self.screens.active.cursor.semantic_content = .output;
+            self.screens.active.cursor.semantic_content_clear_eol = false;
         },
 
         .end_command => {
@@ -1133,9 +1143,8 @@ pub fn semanticPrompt(
             // its reasonable at this point to reset our semantic content
             // state but the spec doesn't really say what to do.
             self.screens.active.cursor.semantic_content = .output;
+            self.screens.active.cursor.semantic_content_clear_eol = false;
         },
-
-        else => {},
     }
 }
 
@@ -1295,6 +1304,13 @@ pub fn index(self: *Terminal) !void {
     // Unset pending wrap state
     self.screens.active.cursor.pending_wrap = false;
 
+    // Always reset any semantic content clear-eol state
+    if (self.screens.active.cursor.semantic_content_clear_eol) {
+        @branchHint(.unlikely);
+        self.screens.active.cursor.semantic_content = .output;
+        self.screens.active.cursor.semantic_content_clear_eol = false;
+    }
+
     // Outside of the scroll region we move the cursor one line down.
     if (self.screens.active.cursor.y < self.scrolling_region.top or
         self.screens.active.cursor.y > self.scrolling_region.bottom)
diff --git a/src/terminal/stream_readonly.zig b/src/terminal/stream_readonly.zig
index 5a5f0d65f..9ffe617bd 100644
--- a/src/terminal/stream_readonly.zig
+++ b/src/terminal/stream_readonly.zig
@@ -999,3 +999,19 @@ test "semantic prompt new_command at column zero" {
     try testing.expectEqual(@as(usize, 0), t.screens.active.cursor.y);
     try testing.expectEqual(.prompt, t.screens.active.cursor.semantic_content);
 }
+
+test "semantic prompt end_prompt_start_input_terminate_eol clears on linefeed" {
+    var t: Terminal = try .init(testing.allocator, .{ .cols = 10, .rows = 10 });
+    defer t.deinit(testing.allocator);
+
+    var s: Stream = .initAlloc(testing.allocator, .init(&t));
+    defer s.deinit();
+
+    // Set input terminated by EOL
+    try s.nextSlice("\x1b]133;I\x07");
+    try testing.expectEqual(.input, t.screens.active.cursor.semantic_content);
+
+    // Linefeed should reset semantic content to output
+    try s.nextSlice("\n");
+    try testing.expectEqual(.output, t.screens.active.cursor.semantic_content);
+}