ropey 1.4.1 fixes the issue

Cargo.lock

@@ -861,9 +861,9 @@ checksum = "8c31b5c4033f8fdde8700e4657be2c497e7288f01515be52168c631e2e4d4086"
 
 [[package]]
 name = "ropey"
-version = "1.4.0"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f6c0c65c416cce36ace31a7cf9bbc8b7f97926df68637f23b5cb39ab7c304d3"
+checksum = "fa0dd9b26e2a102b33d400b7b7d196c81a4014eb96eda90b1c5b48d7215d9633"
 dependencies = [
  "smallvec",
  "str_indices",
@@ -1040,9 +1040,9 @@ checksum = "283baa48c486e4c5e27b4d92c435db9eaceac236a74dab5e3293570e2c3fa4aa"
 
 [[package]]
 name = "syn"
-version = "1.0.88"
+version = "1.0.89"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ebd69e719f31e88618baa1eaa6ee2de5c9a1c004f1e9ecdb58e8352a13f20a01"
+checksum = "ea297be220d52398dcc07ce15a209fce436d361735ac1db700cab3b6cdfb9f54"
 dependencies = [
  "proc-macro2",
  "quote",

helix-core/Cargo.toml

@@ -11,7 +11,6 @@ homepage = "https://helix-editor.com"
 include = ["src/**/*", "README.md"]
 
 [features]
-default = ["unicode-lines"]
 unicode-lines = ["ropey/unicode_lines"]
 
 [dependencies]

helix-core/src/line_ending.rs

@@ -300,9 +300,8 @@ mod line_ending_tests {
     fn line_end_char_index_rope_slice() {
         let r = Rope::from_str("Hello\rworld\nhow\r\nare you?");
         let s = &r.slice(..);
-        assert_eq!(line_end_char_index(s, 0), 5);
+        assert_eq!(line_end_char_index(s, 0), 11);
-        assert_eq!(line_end_char_index(s, 1), 11);
+        assert_eq!(line_end_char_index(s, 1), 15);
-        assert_eq!(line_end_char_index(s, 2), 15);
+        assert_eq!(line_end_char_index(s, 2), 25);
-        assert_eq!(line_end_char_index(s, 3), 25);
     }
 }

helix-term/Cargo.toml

@@ -16,7 +16,6 @@ build = true
 app = true
 
 [features]
-default = ["unicode-lines"]
 unicode-lines = ["helix-core/unicode-lines"]
 
 [[bin]]