feat: add 32767 byte line length limit to DBMS_OUTPUT

Oracle enforces a maximum line length of 32767 bytes per line.
Exceeding this limit raises ORU-10028 error.

- Check line length in PUT_LINE before adding to buffer
- Check accumulated line length in PUT before appending
- Add test cases for line length boundary conditions

Verified against Oracle 23.26 Free.

Fixes #21

Author: rophy

contrib/ivorysql_ora/expected/ora_dbms_output.out

@@ -523,6 +523,48 @@ NOTICE:    [Iteration 1]
 NOTICE:    [Iteration 2]
 NOTICE:    [Iteration 3]
 -- =============================================================================
+-- Section 9: Line Length Limit (32767 bytes)
+-- =============================================================================
+-- Test 9.1: PUT_LINE at exactly 32767 bytes (should succeed)
+DECLARE
+    long_line TEXT := repeat('X', 32767);
+    line TEXT;
+    status INTEGER;
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put_line(long_line);
+    dbms_output.get_line(line, status);
+    RAISE NOTICE 'Test 9.1 - Max line (32767 bytes): length=%, Status=%', length(line), status;
+END;
+/
+NOTICE:  Test 9.1 - Max line (32767 bytes): length=32767, Status=0
+-- Test 9.2: PUT_LINE exceeding 32767 bytes (should fail with ORU-10028)
+DECLARE
+    long_line TEXT := repeat('X', 32768);
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put_line(long_line);
+    RAISE NOTICE 'Test 9.2 - Should not reach here';
+EXCEPTION WHEN OTHERS THEN
+    RAISE NOTICE 'Test 9.2 - Line overflow error: %', SQLERRM;
+END;
+/
+NOTICE:  Test 9.2 - Line overflow error: ORU-10028: line length overflow, limit of 32767 bytes per line
+-- Test 9.3: PUT accumulating to exceed 32767 bytes (should fail with ORU-10028)
+DECLARE
+    chunk TEXT := repeat('X', 32767);
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put(chunk);
+    dbms_output.put('Y');  -- This triggers the overflow
+    dbms_output.new_line();
+    RAISE NOTICE 'Test 9.3 - Should not reach here';
+EXCEPTION WHEN OTHERS THEN
+    RAISE NOTICE 'Test 9.3 - PUT overflow error: %', SQLERRM;
+END;
+/
+NOTICE:  Test 9.3 - PUT overflow error: ORU-10028: line length overflow, limit of 32767 bytes per line
+-- =============================================================================
 -- Cleanup
 -- =============================================================================
 DROP PROCEDURE test_output_proc;

contrib/ivorysql_ora/sql/ora_dbms_output.sql

@@ -500,6 +500,48 @@ BEGIN
 END;
 /
 
+-- =============================================================================
+-- Section 9: Line Length Limit (32767 bytes)
+-- =============================================================================
+-- Test 9.1: PUT_LINE at exactly 32767 bytes (should succeed)
+DECLARE
+    long_line TEXT := repeat('X', 32767);
+    line TEXT;
+    status INTEGER;
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put_line(long_line);
+    dbms_output.get_line(line, status);
+    RAISE NOTICE 'Test 9.1 - Max line (32767 bytes): length=%, Status=%', length(line), status;
+END;
+/
+
+-- Test 9.2: PUT_LINE exceeding 32767 bytes (should fail with ORU-10028)
+DECLARE
+    long_line TEXT := repeat('X', 32768);
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put_line(long_line);
+    RAISE NOTICE 'Test 9.2 - Should not reach here';
+EXCEPTION WHEN OTHERS THEN
+    RAISE NOTICE 'Test 9.2 - Line overflow error: %', SQLERRM;
+END;
+/
+
+-- Test 9.3: PUT accumulating to exceed 32767 bytes (should fail with ORU-10028)
+DECLARE
+    chunk TEXT := repeat('X', 32767);
+BEGIN
+    dbms_output.enable(100000);
+    dbms_output.put(chunk);
+    dbms_output.put('Y');  -- This triggers the overflow
+    dbms_output.new_line();
+    RAISE NOTICE 'Test 9.3 - Should not reach here';
+EXCEPTION WHEN OTHERS THEN
+    RAISE NOTICE 'Test 9.3 - PUT overflow error: %', SQLERRM;
+END;
+/
+
 -- =============================================================================
 -- Cleanup
 -- =============================================================================

contrib/ivorysql_ora/src/builtin_packages/dbms_output/dbms_output.c

@@ -59,6 +59,9 @@ typedef struct DbmsOutputBuffer
 /* Global buffer - one per backend process */
 static DbmsOutputBuffer *output_buffer = NULL;
 
+/* Oracle line length limit: 32767 bytes per line */
+#define DBMS_OUTPUT_MAX_LINE_LENGTH 32767
+
 /* Internal function declarations */
 static void init_output_buffer(int buffer_size);
 static void cleanup_output_buffer(void);
@@ -311,12 +314,14 @@ ora_dbms_output_disable(PG_FUNCTION_ARGS)
  * Output a line to the buffer (with newline).
  * If there's pending PUT text, append it first (Oracle behavior).
  * Oracle behavior: NULL stores actual NULL in buffer (not empty string).
+ * Oracle behavior: raises ORU-10028 if line exceeds 32767 bytes.
  */
 Datum
 ora_dbms_output_put_line(PG_FUNCTION_ARGS)
 {
 	char	   *line_str;
 	bool		is_null = false;
+	int			line_len = 0;
 
 	/* Silently discard if buffer not enabled (Oracle behavior) */
 	if (output_buffer == NULL || !output_buffer->enabled)
@@ -332,11 +337,19 @@ ora_dbms_output_put_line(PG_FUNCTION_ARGS)
 	{
 		text	   *line_text = PG_GETARG_TEXT_PP(0);
 		line_str = text_to_cstring(line_text);
+		line_len = strlen(line_str);
 	}
 
 	/* If there's pending PUT text, append it first (Oracle behavior) */
 	if (output_buffer->current_line->len > 0)
 	{
+		/* Check line length limit BEFORE appending (Oracle behavior) */
+		if (output_buffer->current_line->len + line_len > DBMS_OUTPUT_MAX_LINE_LENGTH)
+			ereport(ERROR,
+					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+					 errmsg("ORU-10028: line length overflow, limit of %d bytes per line",
+							DBMS_OUTPUT_MAX_LINE_LENGTH)));
+
 		/* Append non-NULL text to current line */
 		if (!is_null)
 			appendStringInfoString(output_buffer->current_line, line_str);
@@ -345,7 +358,14 @@ ora_dbms_output_put_line(PG_FUNCTION_ARGS)
 	}
 	else
 	{
-		/* No pending PUT text, just add the line (may be NULL) */
+		/* No pending PUT text - check line length for direct add */
+		if (line_len > DBMS_OUTPUT_MAX_LINE_LENGTH)
+			ereport(ERROR,
+					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+					 errmsg("ORU-10028: line length overflow, limit of %d bytes per line",
+							DBMS_OUTPUT_MAX_LINE_LENGTH)));
+
+		/* Just add the line (may be NULL) */
 		add_line_to_buffer(line_str);
 	}
 
@@ -358,25 +378,36 @@ ora_dbms_output_put_line(PG_FUNCTION_ARGS)
  * Output text without newline (accumulates in current_line).
  * Oracle behavior: not retrievable until NEW_LINE or PUT_LINE is called.
  * Oracle behavior: NULL is treated as empty string (appends nothing).
+ * Oracle behavior: raises ORU-10028 if line exceeds 32767 bytes.
  */
 Datum
 ora_dbms_output_put(PG_FUNCTION_ARGS)
 {
 	char	   *str;
+	int			str_len;
 
 	/* Silently discard if buffer not enabled */
 	if (output_buffer == NULL || !output_buffer->enabled)
 		PG_RETURN_VOID();
 
 	/* Handle NULL argument - treat as empty string (Oracle behavior) */
 	if (PG_ARGISNULL(0))
-		str = "";
-	else
+		PG_RETURN_VOID();  /* NULL appends nothing */
+
 	{
 		text	   *text_arg = PG_GETARG_TEXT_PP(0);
 		str = text_to_cstring(text_arg);
 	}
 
+	str_len = strlen(str);
+
+	/* Check line length limit BEFORE appending (Oracle behavior) */
+	if (output_buffer->current_line->len + str_len > DBMS_OUTPUT_MAX_LINE_LENGTH)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("ORU-10028: line length overflow, limit of %d bytes per line",
+						DBMS_OUTPUT_MAX_LINE_LENGTH)));
+
 	/* Accumulate in current_line without creating a line yet */
 	appendStringInfoString(output_buffer->current_line, str);