From 0140e0cdf901d28ddf6cd16859a055e3815e01cc Mon Sep 17 00:00:00 2001
From: Angelo <git@angelo.fyi>
Date: Thu, 13 Aug 2026 09:32:22 +0700
Subject: [PATCH 1/4] fix(point): validate newlines

---
 src/point.rs | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/point.rs b/src/point.rs
index c6423df..44edf38 100644
--- a/src/point.rs
+++ b/src/point.rs
@@ -259,6 +259,37 @@ impl Point {
                 self.measurement
             )));
         }
+        // VALIDATION: '\n' characters are not supported
+        for (k, v) in self.tags() {
+            if k.contains('\n') || v.contains('\n') {
+                return Err(Error::Config(
+                    format!(
+                        "tag '{k}' contains a line break which is unsupported in line protocol; point '{}'",
+                        self.measurement
+                    )
+                ));
+            }
+        }
+        for (k, v) in self.fields() {
+            if k.contains('\n') {
+                return Err(Error::Config(
+                    format!(
+                        "field '{k}' contains a line break which is unsupported in line protocol; point '{}'",
+                        self.measurement
+                    )
+                ));
+            }
+            if let FieldValue::String(s) = v {
+                if s.contains('\n') {
+                    return Err(Error::Config(
+                        format!(
+                            "field '{k}' contains a line break which is unsupported in line protocol; point '{}'",
+                            self.measurement
+                        )
+                    ));
+                }
+            }
+        }
 
         // Measurement
         write_escaped_measurement(buf, &self.measurement);

From 5a1a968f867d670a78e290c92e8872b614e2310d Mon Sep 17 00:00:00 2001
From: Angelo <git@angelo.fyi>
Date: Thu, 13 Aug 2026 09:50:56 +0700
Subject: [PATCH 2/4] chore: add changes to changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 01737ca..a80dacd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## 0.4.0 [unreleased]
 
+### Bug Fixes
+
+1. [#49](https://github.com/InfluxCommunity/influxdb3-rust/pull/49): Extra validation on `Point#write_line_protocol()` to error out if fields contains any newline (`\n`) character.
+
 ## 0.3.0 [2026-08-27]
 
 > ⚠️ This release requires Rust 1.91 or later.

From 105d09f00b7c1c7e25edbebf85b7cd2878a4c041 Mon Sep 17 00:00:00 2001
From: Angelo <git@angelo.fyi>
Date: Thu, 27 Aug 2026 17:13:46 +0700
Subject: [PATCH 3/4] test: add tests for linebreak validation

---
 tests/point_tests.rs | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tests/point_tests.rs b/tests/point_tests.rs
index 4c2bd73..9eff600 100644
--- a/tests/point_tests.rs
+++ b/tests/point_tests.rs
@@ -80,3 +80,31 @@ fn last_write_wins() {
     assert_eq!(lp.matches("v=").count(), 1);
     assert!(lp.contains("v=2i"));
 }
+
+#[test]
+#[should_panic = "contains a line break"]
+fn tag_names_should_reject_newlines() {
+    Point::new("m")
+        .tag("t\nag", "value")
+        .field("v", 1)
+        .to_line_protocol(Precision::Nanosecond)
+        .unwrap();
+}
+#[test]
+#[should_panic = "contains a line break"]
+fn tag_values_should_reject_newlines() {
+    Point::new("m")
+        .tag("tag", "val\nue")
+        .field("v", 1)
+        .to_line_protocol(Precision::Nanosecond)
+        .unwrap();
+}
+#[test]
+#[should_panic = "contains a line break"]
+fn field_names_should_reject_newlines() {
+    Point::new("m")
+        .tag("tag", "value")
+        .field("fi\neld", 1)
+        .to_line_protocol(Precision::Nanosecond)
+        .unwrap();
+}

From ef2e8f4f1938acb49fd3d7f11b2f54380a34e7dd Mon Sep 17 00:00:00 2001
From: Ales Pour <ales.pour@bonitoo.io>
Date: Thu, 27 Aug 2026 14:15:41 +0200
Subject: [PATCH 4/4] test: add coverage for newlines in string field values

---
 tests/point_tests.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/point_tests.rs b/tests/point_tests.rs
index 9eff600..ae588a4 100644
--- a/tests/point_tests.rs
+++ b/tests/point_tests.rs
@@ -108,3 +108,12 @@ fn field_names_should_reject_newlines() {
         .to_line_protocol(Precision::Nanosecond)
         .unwrap();
 }
+
+#[test]
+#[should_panic = "contains a line break"]
+fn field_values_should_reject_newlines() {
+    Point::new("m")
+        .field("field", "val\nue")
+        .to_line_protocol(Precision::Nanosecond)
+        .unwrap();
+}