Fix case where the from clause is misidentified.

fixes spring-projects#2260

Added a zero-width word boundary to the regex that identifies the from clause.  This is used in alias detection for order by clauses.

Author: darinmanica

src/main/java/org/springframework/data/jpa/repository/query/QueryUtils.java

@@ -138,7 +138,7 @@ public abstract class QueryUtils {
 	static {
 
 		StringBuilder builder = new StringBuilder();
-		builder.append("(?<=from)"); // from as starting delimiter
+		builder.append("(?<=\\bfrom)"); // from as starting delimiter
 		builder.append("(?:\\s)+"); // at least one space separating
 		builder.append(IDENTIFIER_GROUP); // Entity name, can be qualified (any
 		builder.append("(?:\\sas)*"); // exclude possible "as" keyword

src/test/java/org/springframework/data/jpa/repository/query/QueryUtilsUnitTests.java

@@ -130,6 +130,9 @@ void detectsAliasCorrectly() throws Exception {
 		assertThat(detectAlias(
 				"(from Foo f max(f) ((((select * from Foo f2 (from Foo f3) max(*)) (from Foo f4)) max(f5)) (f6)) (from Foo f7))"))
 						.isEqualTo("f");
+		assertThat(detectAlias(
+				"SELECT e FROM DbEvent e WHERE (CAST(:modifiedFrom AS date) IS NULL OR e.modificationDate >= :modifiedFrom)"))
+						.isEqualTo("e");
 	}
 
 	@Test // GH-2260