fix: treat a positional parameter '?' as a valid end of the ternary then-branch

A bare '?' (anonymous token, no kind constant) was missing from
canEndExpression(), so a ternary whose then-branch ends with a positional
parameter was silently misread as a jsonb operator: SELECT a ? ? : c FROM t
parsed as JsonOperator(a, JsonExpression(?:c)) instead of
TernaryExpression(a, JdbcParameter, c). Recognize it by image, like the
closing brackets, and pin the AST shape with a regression test.

Follow-up to #2476.

Signed-off-by: 付典 <fudianchn@gmail.com>

Author: fudianchn

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -280,7 +280,9 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
      * in operand position instead (directly after an operator, e.g. `x = :name`
      * or directly after the leading "?") starts a JDBC named parameter.
      * DATA_TYPE tokens end expressions as well, because a cast's target type
-     * (`b :: int`) or a bare type keyword closes the then-branch.
+     * (`b :: int`) or a bare type keyword closes the then-branch. The bare "?"
+     * positional parameter has no token-kind constant (anonymous token), so it
+     * is recognized by its image, like the closing brackets.
      */
     private boolean canEndExpression(Token t) {
         if (t == null) {
@@ -294,7 +296,8 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
                 return true;
             default:
                 return (t.kind >= MIN_NON_RESERVED_WORD && t.kind <= MAX_NON_RESERVED_WORD)
-                        || ")".equals(t.image) || "]".equals(t.image);
+                        || ")".equals(t.image) || "]".equals(t.image)
+                        || "?".equals(t.image);
         }
     }
 

src/test/java/net/sf/jsqlparser/expression/TernaryExpressionTest.java

@@ -10,6 +10,7 @@
 package net.sf.jsqlparser.expression;
 
 import net.sf.jsqlparser.JSQLParserException;
+import net.sf.jsqlparser.expression.operators.arithmetic.Addition;
 import net.sf.jsqlparser.parser.CCJSqlParserUtil;
 import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
 import net.sf.jsqlparser.expression.operators.conditional.OrExpression;
@@ -65,6 +66,8 @@ void testIssue2436() throws JSQLParserException {
             "SELECT a IS NULL ? 'x' : y FROM t",
             // jdbc parameters as branches
             "SELECT a ? ? : c FROM t",
+            "SELECT a ? b + ? : c FROM t",
+            "SELECT a ? ? : ? FROM t",
             "SELECT a ? b : ? FROM t",
             "SELECT * FROM t WHERE x = ? AND y ? z : w",
             // case expression inside a branch
@@ -156,6 +159,23 @@ void testTernaryWithCastThenBranch() throws JSQLParserException {
         Assertions.assertTrue(ternary.getThenExpression() instanceof CastExpression);
     }
 
+    @Test
+    void testTernaryWithPositionalParameterThenBranch() throws JSQLParserException {
+        // regression guard: a bare "?" positional parameter is a complete
+        // expression, so the ":" after it closes the ternary instead of being
+        // skipped in favor of the jsonb reading
+        Select select = (Select) CCJSqlParserUtil.parse("SELECT a ? ? : c FROM t");
+        TernaryExpression ternary = (TernaryExpression) ((PlainSelect) select).getSelectItem(0)
+                .getExpression();
+        Assertions.assertTrue(ternary.getThenExpression() instanceof JdbcParameter);
+        Assertions.assertTrue(ternary.getElseExpression() instanceof Column);
+
+        // a positional parameter as the LAST token of the then-branch, too
+        select = (Select) CCJSqlParserUtil.parse("SELECT a ? b + ? : c FROM t");
+        ternary = (TernaryExpression) ((PlainSelect) select).getSelectItem(0).getExpression();
+        Assertions.assertTrue(ternary.getThenExpression() instanceof Addition);
+    }
+
     @ParameterizedTest
     @ValueSource(strings = {
             // PostgreSQL jsonb operator combined with JDBC named parameters