Fix NoSuchElementException when rlike with empty pattern (#10914)

Signed-off-by: Haoyang Li <[email protected]>

docs/compatibility.md

@@ -495,6 +495,7 @@ The following regular expression patterns are not yet supported on the GPU and w
 - Character classes that use union, intersection, or subtraction semantics, such as `[a-d[m-p]]`, `[a-z&&[def]]`,
   or `[a-z&&[^bc]]`
 - Empty groups: `()`
+- Empty pattern: `""`
 
 Work is ongoing to increase the range of regular expressions that can run on the GPU.
 

integration_tests/src/main/python/regexp_test.py

@@ -790,6 +790,15 @@ def test_rlike_fallback_empty_group():
             'RLike',
         conf=_regexp_conf)
 
+@allow_non_gpu('ProjectExec', 'RLike')
+def test_rlike_fallback_empty_pattern():
+    gen = mk_str_gen('[abcd]{1,3}')
+    assert_gpu_fallback_collect(
+            lambda spark: unary_op_df(spark, gen).selectExpr(
+                'a rlike ""'),
+            'RLike',
+        conf=_regexp_conf)
+
 def test_rlike_escape():
     gen = mk_str_gen('[ab]{0,2};?[\\-\\+]{0,2}/?')
     assert_gpu_and_cpu_are_equal_collect(

sql-plugin/src/main/scala/com/nvidia/spark/rapids/RegexParser.scala

@@ -2045,10 +2045,10 @@ object RegexRewrite {
   private def getPrefixRangePattern(astLs: collection.Seq[RegexAST]): 
       Option[(String, Int, Int, Int)] = {
     val haveLiteralPrefix = isliteralString(astLs.dropRight(1))
-    val endsWithRange = astLs.last match {
-      case RegexRepetition(
-          RegexCharacterClass(false,ListBuffer(RegexCharacterRange(a,b))), 
-          quantifier) => {
+    val endsWithRange = astLs.lastOption match {
+      case Some(RegexRepetition(
+          RegexCharacterClass(false, ListBuffer(RegexCharacterRange(a,b))), 
+          quantifier)) => {
         val (start, end) = (a, b) match {
           case (RegexChar(start), RegexChar(end)) => (start, end)
           case _ => return None