#921 Do not parse escapes within double quotes

Author: mrotteveel

src/docs/asciidoc/release_notes.adoc

@@ -48,6 +48,7 @@ This results in two minor breaking changes:
 +
 ** Reserved words are no longer considered simple identifiers by `enquoteIdentifier` and `isSimpleIdentifier` and will be quoted (or -- for dialect 1 -- result in a `SQLFeatureNotSupportedException`)
 ** Presence of the NUL character (U+0000) in an identifier passed to `enquoteIdentifier` will result in a `SQLSyntaxErrorException`
+* Fixed: JDBC escapes should not be parsed inside dialect 3 delimited identifiers or dialect 1 string literals (https://github.com/FirebirdSQL/jaybird/issues/921[#921])
 
 === Jaybird 6.0.4
 

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

@@ -116,7 +116,7 @@ public static String parse(final String sql) throws SQLException {
             case INITIAL_STATE -> {
                 // Ignore leading whitespace
             }
-            case NORMAL_STATE, LITERAL_STATE,
+            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 -> {
@@ -375,6 +375,7 @@ 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;
@@ -393,6 +394,15 @@ 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

@@ -361,22 +361,31 @@ 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 + "'";
 
-        String parseResult = FBEscapedParser.toNativeSql(input);
-        assertEquals(input, parseResult, "Unexpected output");
+        assertEquals(input, FBEscapedParser.toNativeSql(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, FBEscapedParser.toNativeSql(input), "Unexpected output");
     }
+
 }