Merge pull request #6360 from thundernest/fix_SmtpResponseParser_logging

Clear log buffer before reading EHLO response

mail/protocols/smtp/src/main/java/com/fsck/k9/mail/transport/smtp/SmtpResponseParser.kt

@@ -33,6 +33,8 @@ internal class SmtpResponseParser(
     }
 
     fun readHelloResponse(): SmtpHelloResponse {
+        logBuffer.clear()
+
         val replyCode = readReplyCode()
 
         if (replyCode != 250) {

mail/protocols/smtp/src/test/java/com/fsck/k9/mail/transport/smtp/SmtpResponseParserTest.kt

@@ -219,6 +219,30 @@ class SmtpResponseParserTest {
             .isEqualTo("Ignoring EHLO keyword line: KEYWORD para${"\t"}meter")
     }
 
+    @Test
+    fun `error in EHLO response after successfully reading greeting`() {
+        val input = """
+            220 Greeting
+            INVALID
+        """.toPeekableInputStream()
+        val parser = SmtpResponseParser(logger, input)
+        parser.readGreeting()
+
+        assertFailsWithMessage("Unexpected character: I (73)") {
+            parser.readHelloResponse()
+        }
+
+        assertThat(logger.logEntries).containsExactly(
+            LogEntry(
+                throwable = null,
+                message = """
+                    SMTP response data on parser error:
+                    I
+                """.trimIndent()
+            )
+        )
+    }
+
     @Test
     fun `positive response`() {
         val input = "200 OK".toPeekableInputStream()