From 589942f52c6f0b12f0a1f469156386529817bc01 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 20 Dec 2025 11:11:54 -1000
Subject: [PATCH] simplify logic

---
 esphome/components/syslog/esphome_syslog.cpp | 16 ++++---------
 tests/integration/fixtures/syslog.yaml       |  5 ++++
 tests/integration/test_syslog.py             | 24 ++++++++++++++++++++
 3 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/esphome/components/syslog/esphome_syslog.cpp b/esphome/components/syslog/esphome_syslog.cpp
index 8e7f809ecc..2fef1889f1 100644
--- a/esphome/components/syslog/esphome_syslog.cpp
+++ b/esphome/components/syslog/esphome_syslog.cpp
@@ -55,18 +55,12 @@ void Syslog::log_(const int level, const char *tag, const char *message, size_t
   offset = ret;
   remaining -= ret;
 
-  // Write timestamp directly into packet (RFC 5424: use "-" if time not valid)
+  // Write timestamp directly into packet (RFC 5424: use "-" if time not valid or strftime fails)
   auto now = this->time_->now();
-  if (now.is_valid()) {
-    size_t written = now.strftime(packet + offset, remaining, "%b %e %H:%M:%S");
-    if (written > 0) {
-      offset += written;
-      remaining -= written;
-    } else if (remaining > 0) {
-      // strftime failed; write NILVALUE as fallback
-      packet[offset++] = '-';
-      remaining--;
-    }
+  size_t ts_written = now.is_valid() ? now.strftime(packet + offset, remaining, "%b %e %H:%M:%S") : 0;
+  if (ts_written > 0) {
+    offset += ts_written;
+    remaining -= ts_written;
   } else if (remaining > 0) {
     packet[offset++] = '-';
     remaining--;
diff --git a/tests/integration/fixtures/syslog.yaml b/tests/integration/fixtures/syslog.yaml
index fee00eb8ff..df376087e3 100644
--- a/tests/integration/fixtures/syslog.yaml
+++ b/tests/integration/fixtures/syslog.yaml
@@ -16,6 +16,11 @@ api:
               "DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD"
               "EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE"
               "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF");
+    - service: log_short_message
+      then:
+        - lambda: |-
+            // Log a short message that should arrive complete (not truncated)
+            ESP_LOGI("shorttest", "BEGIN|SHORT_MESSAGE_CONTENT|FINISH");
 
 logger:
   level: DEBUG
diff --git a/tests/integration/test_syslog.py b/tests/integration/test_syslog.py
index fee493c5cb..b31a19392c 100644
--- a/tests/integration/test_syslog.py
+++ b/tests/integration/test_syslog.py
@@ -258,3 +258,27 @@ async def test_syslog(
             assert "|END" not in trunc_msg, (
                 "Message should be truncated before END marker"
             )
+
+            # Test short message - should arrive complete (not truncated)
+            short_service = next(
+                (s for s in services if s.name == "log_short_message"), None
+            )
+            assert short_service is not None, "log_short_message service not found"
+
+            await client.execute_service(short_service, {})
+
+            try:
+                short_msg = await receiver.wait_for_pattern(r"shorttest.*BEGIN\|")
+            except TimeoutError:
+                pytest.fail(
+                    f"Short test message not received. Got: {receiver.messages[-10:]}"
+                )
+
+            # Verify short message arrived complete with both markers
+            assert "BEGIN|" in short_msg, "Short message missing BEGIN marker"
+            assert "|FINISH" in short_msg, (
+                f"Short message truncated unexpectedly: {short_msg}"
+            )
+            assert "SHORT_MESSAGE_CONTENT" in short_msg, (
+                f"Short message content missing: {short_msg}"
+            )