#921 Do not parse escapes within double quotes

Author: mrotteveel

src/main/org/firebirdsql/jdbc/escape/FBEscapedParser.java

@@ -2,7 +2,7 @@
  SPDX-FileCopyrightText: Copyright 2001-2002 David Jencks
  SPDX-FileCopyrightText: Copyright 2002-2005 Roman Rokytskyy
  SPDX-FileCopyrightText: Copyright 2003 Blas Rodriguez Somoza
- SPDX-FileCopyrightText: Copyright 2012-2025 Mark Rotteveel
+ SPDX-FileCopyrightText: Copyright 2012-2026 Mark Rotteveel
  SPDX-License-Identifier: LGPL-2.1-or-later
 */
 package org.firebirdsql.jdbc.escape;
@@ -133,9 +133,9 @@ public String toNative(String sql) throws SQLException {
             case INITIAL_STATE -> {
                 // Ignore leading whitespace
             }
-            case NORMAL_STATE, LITERAL_STATE,
-                    START_LINE_COMMENT, LINE_COMMENT, START_BLOCK_COMMENT, BLOCK_COMMENT, END_BLOCK_COMMENT,
-                    POSSIBLE_Q_LITERAL_ENTER -> buffer.append(currentChar);
+            case NORMAL_STATE, LITERAL_STATE, DELIMITED_IDENTIFIER,
+                 START_LINE_COMMENT, LINE_COMMENT, START_BLOCK_COMMENT, BLOCK_COMMENT, END_BLOCK_COMMENT,
+                 POSSIBLE_Q_LITERAL_ENTER -> buffer.append(currentChar);
             case ESCAPE_ENTER_STATE -> {
                 bufferStack.push(buffer);
                 buffer = new StringBuilder();
@@ -393,6 +393,7 @@ protected ParserState nextState(char inputChar) throws FBSQLParseException {
             protected ParserState nextState(char inputChar) {
                 return switch (inputChar) {
                     case '\'' -> LITERAL_STATE;
+                    case '"' -> DELIMITED_IDENTIFIER;
                     case '{' -> ESCAPE_ENTER_STATE;
                     case '}' -> ESCAPE_EXIT_STATE;
                     case '-' -> START_LINE_COMMENT;
@@ -411,6 +412,15 @@ protected ParserState nextState(char inputChar) {
                 return (inputChar == '\'') ? NORMAL_STATE : LITERAL_STATE;
             }
         },
+        /**
+         * Dialect 3 delimited identifier or dialect 1 literal text (text inside double quotes).
+         */
+        DELIMITED_IDENTIFIER {
+            @Override
+            protected ParserState nextState(char inputChar) {
+                return (inputChar == '"') ? NORMAL_STATE : DELIMITED_IDENTIFIER;
+            }
+        },
         /**
          * Start of JDBC escape ({ character encountered).
          */

src/test/org/firebirdsql/jdbc/escape/FBEscapedParserTest.java

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2012-2025 Mark Rotteveel
+// SPDX-FileCopyrightText: Copyright 2012-2026 Mark Rotteveel
 // SPDX-License-Identifier: LGPL-2.1-or-later
 package org.firebirdsql.jdbc.escape;
 
@@ -331,21 +331,31 @@ void testQLiteral_InLiteralEndOfString_throwsParseException() {
                 "Unexpected end of string at parser state Q_LITERAL_START");
     }
 
-    @Test
-    void testQLiteralSpecials() throws Exception {
-        checkQLiteralSpecialsBalancedStartEnd('(', ')');
-        checkQLiteralSpecialsBalancedStartEnd(')', ')');
-        checkQLiteralSpecialsBalancedStartEnd('{', '}');
-        checkQLiteralSpecialsBalancedStartEnd('}', '}');
-        checkQLiteralSpecialsBalancedStartEnd('[', ']');
-        checkQLiteralSpecialsBalancedStartEnd(']', ']');
-        checkQLiteralSpecialsBalancedStartEnd('<', '>');
-        checkQLiteralSpecialsBalancedStartEnd('>', '>');
-    }
-
-    private void checkQLiteralSpecialsBalancedStartEnd(char start, char end) throws Exception {
+    @ParameterizedTest
+    @CsvSource(useHeadersInDisplayName = true, textBlock = """
+            start, end
+            (,     )
+            ),     )
+            {,     }
+            [,     ]
+            ],     ]
+            <,     >
+            >,     >
+            """)
+    void checkQLiteralSpecialsBalancedStartEnd(char start, char end) throws Exception {
         final String input = "q'" + start + " {fn EXP(2)} " + end + "'";
 
         assertEquals(input, toNative(input), "Unexpected output");
     }
+
+    @ParameterizedTest
+    @ValueSource(strings = {
+            "'{fn EXP(2)}'",
+            "q'{{fn EXP(2)}}'",
+            "\"{fn EXP(2)}\""
+    })
+    void escapesInLiteralsOrDelimitedIdentifiers_notAnEscape(String input) throws Exception {
+        assertEquals(input, toNative(input), "Unexpected output");
+    }
+
 }