From 26c6f97e08698f91298186d9c545ea1fe3102552 Mon Sep 17 00:00:00 2001
From: Steven Phillips <steven@dremio.com>
Date: Fri, 4 Mar 2016 20:29:26 -0800
Subject: [PATCH] DRILL-4486: Fix expression serialization escaping

---
 .../common/expression/ExpressionStringBuilder.java  | 13 ++++++++++---
 .../drill/common/expression/parser/TreeTest.java    | 12 ++++++++++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/logical/src/main/java/org/apache/drill/common/expression/ExpressionStringBuilder.java b/logical/src/main/java/org/apache/drill/common/expression/ExpressionStringBuilder.java
index c29b9b02d1a..85547bc7cda 100644
--- a/logical/src/main/java/org/apache/drill/common/expression/ExpressionStringBuilder.java
+++ b/logical/src/main/java/org/apache/drill/common/expression/ExpressionStringBuilder.java
@@ -56,6 +56,13 @@ public static void toString(LogicalExpression expr, StringBuilder sb) {
     expr.accept(INSTANCE, sb);
   }
 
+  public static String escapeSingleQuote(String input) {
+    return input.replaceAll("(['\\\\])", "\\\\$1");
+  }
+
+  public static String escapeBackTick(String input) {
+    return input.replaceAll("([`\\\\])", "\\\\$1");
+  }
 
   @Override
   public Void visitFunctionCall(FunctionCall call, StringBuilder sb) throws RuntimeException {
@@ -119,14 +126,14 @@ public Void visitSchemaPath(SchemaPath path, StringBuilder sb) throws RuntimeExc
       throw new IllegalStateException("Drill doesn't currently support top level arrays");
     }
     sb.append('`');
-    sb.append(seg.getNameSegment().getPath());
+    sb.append(escapeBackTick(seg.getNameSegment().getPath()));
     sb.append('`');
 
     while ( (seg = seg.getChild()) != null) {
       if (seg.isNamed()) {
         sb.append('.');
         sb.append('`');
-        sb.append(seg.getNameSegment().getPath());
+        sb.append(escapeBackTick(seg.getNameSegment().getPath()));
         sb.append('`');
       } else {
         sb.append('[');
@@ -224,7 +231,7 @@ public Void visitBooleanConstant(BooleanExpression e, StringBuilder sb) throws R
   @Override
   public Void visitQuotedStringConstant(QuotedString e, StringBuilder sb) throws RuntimeException {
     sb.append("'");
-    sb.append(e.value);
+    sb.append(escapeSingleQuote(e.value));
     sb.append("'");
     return null;
   }
diff --git a/logical/src/test/java/org/apache/drill/common/expression/parser/TreeTest.java b/logical/src/test/java/org/apache/drill/common/expression/parser/TreeTest.java
index c8f6219dabb..fe135371da3 100644
--- a/logical/src/test/java/org/apache/drill/common/expression/parser/TreeTest.java
+++ b/logical/src/test/java/org/apache/drill/common/expression/parser/TreeTest.java
@@ -31,6 +31,18 @@
 public class TreeTest extends DrillTest {
   private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(TreeTest.class);
 
+  @Test
+  public void escapeStringLiteral() throws Exception {
+    String expr = "func(`identifier`, '\\\\d+', 0, 'fjds')";
+    testExpressionParsing(expr);
+  }
+
+  @Test
+  public void escapeQuotedIdentifier() throws Exception {
+    String expr = "`a\\\\b` + `c'd`";
+    testExpressionParsing(expr);
+  }
+
   @Test
   public void testIfWithCase() throws Exception{
     testExpressionParsing("if ($F1) then case when (_MAP.R_NAME = 'AFRICA') then 2 else 4 end else if(4==3) then 1 else if(x==3) then 7 else (if(2==1) then 6 else 4 end) end");