From de37405f8e77eb111396c90298480870d40617d2 Mon Sep 17 00:00:00 2001
From: Alon Ziv <nolaviz@google.com>
Date: Sun, 8 Dec 2024 06:32:20 +0000
Subject: [PATCH] Re-enable bare `<sep>` when incompatibleImprovements <
 2.3.34.

---
 freemarker-core/src/main/javacc/freemarker/core/FTL.jj   | 4 +++-
 .../src/test/java/freemarker/core/SepParsingBugTest.java | 9 +++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/freemarker-core/src/main/javacc/freemarker/core/FTL.jj b/freemarker-core/src/main/javacc/freemarker/core/FTL.jj
index 72c191de7..c517271c1 100644
--- a/freemarker-core/src/main/javacc/freemarker/core/FTL.jj
+++ b/freemarker-core/src/main/javacc/freemarker/core/FTL.jj
@@ -943,7 +943,9 @@ TOKEN:
     |
     <ITEMS : <START_TAG> "items" (<BLANK>)+ <AS> <BLANK>> { handleTagSyntaxAndSwitch(matchedToken, FM_EXPRESSION); }
     |
-    <SEP : <START_TAG> "sep" <CLOSE_TAG1>> { handleTagSyntaxAndSwitch(matchedToken, DEFAULT); }
+    <SEP : <START_TAG> "sep" <CLOSE_TAG1>> {
+        if (incompatibleImprovements >= _VersionInts.V_2_3_24) handleTagSyntaxAndSwitch(matchedToken, DEFAULT);
+    }
     |
     <FOREACH : <START_TAG> "for" ("e" | "E") "ach" <BLANK>> {
         handleTagSyntaxAndSwitch(matchedToken, getTagNamingConvention(matchedToken, 3), FM_EXPRESSION);
diff --git a/freemarker-core/src/test/java/freemarker/core/SepParsingBugTest.java b/freemarker-core/src/test/java/freemarker/core/SepParsingBugTest.java
index f85e841cb..3e835d769 100644
--- a/freemarker-core/src/test/java/freemarker/core/SepParsingBugTest.java
+++ b/freemarker-core/src/test/java/freemarker/core/SepParsingBugTest.java
@@ -31,6 +31,7 @@ public class SepParsingBugTest extends TemplateTest {
     
     @Test
     public void testAutodetectTagSyntax() throws TemplateException, IOException {
+        getConfiguration().setIncompatibleImprovements(Configuration.VERSION_2_3_24);
         getConfiguration().setTagSyntax(Configuration.AUTO_DETECT_TAG_SYNTAX);
         assertOutput("<#list [1, 2] as i>${i}<#sep>, </#list>", "1, 2");
         assertOutput("[#list [1, 2] as i]${i}[#sep], [/#list]", "1, 2");
@@ -42,6 +43,7 @@ public void testAutodetectTagSyntax() throws TemplateException, IOException {
 
     @Test
     public void testAngleBracketsTagSyntax() throws TemplateException, IOException {
+        getConfiguration().setIncompatibleImprovements(Configuration.VERSION_2_3_24);
         getConfiguration().setTagSyntax(Configuration.ANGLE_BRACKET_TAG_SYNTAX);
         assertOutput("<#list [1, 2] as i>${i}<#sep>, </#list>", "1, 2");
         assertOutput("[#list [1, 2] as i]${i!'-'}[#sep], [/#list]", "[#list [1, 2] as i]-[#sep], [/#list]");
@@ -53,6 +55,7 @@ public void testAngleBracketsTagSyntax() throws TemplateException, IOException {
 
     @Test
     public void testSquareBracketTagSyntax() throws TemplateException, IOException {
+        getConfiguration().setIncompatibleImprovements(Configuration.VERSION_2_3_24);
         getConfiguration().setTagSyntax(Configuration.SQUARE_BRACKET_TAG_SYNTAX);
         assertOutput("<#list [1, 2] as i>${i!'-'}<#sep>, </#list>", "<#list [1, 2] as i>-<#sep>, </#list>");
         assertOutput("[#list [1, 2] as i]${i}[#sep], [/#list]", "1, 2");
@@ -62,4 +65,10 @@ public void testSquareBracketTagSyntax() throws TemplateException, IOException {
         assertErrorContains("[#sep]", "#sep must be inside");
     }
 
+    @Test
+    public void testLegacyTagSyntax() throws TemplateException, IOException {
+        getConfiguration().setIncompatibleImprovements(Configuration.VERSION_2_3_23);
+        getConfiguration().setTagSyntax(Configuration.AUTO_DETECT_TAG_SYNTAX);
+        assertOutput("<#list [1, 2] as i>${i}<sep>, </#list>", "1, 2");
+    }
 }