From 3ca5f7654e333cb9611cc1a23357fa3d5257c3f2 Mon Sep 17 00:00:00 2001
From: Mark Keller <mark.keller@snowflake.com>
Date: Mon, 13 Nov 2023 17:17:05 +0000
Subject: [PATCH] SNOW-950417 fix quoted name matching for new lines (#1125)

---
 CHANGELOG.md                              |  6 ++++++
 src/snowflake/snowpark/_internal/utils.py |  3 ++-
 tests/integ/test_dataframe.py             | 17 +++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9231212f625..eea76a2ca68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Release History
 
+## 1.10.1 (TBD)
+
+### Bug Fixes
+
+- DataFrame column names qouting check now supports newline characters.
+
 ## 1.10.0 (2023-11-03)
 
 ### New Features
diff --git a/src/snowflake/snowpark/_internal/utils.py b/src/snowflake/snowpark/_internal/utils.py
index 6105a633254..a104181acaf 100644
--- a/src/snowflake/snowpark/_internal/utils.py
+++ b/src/snowflake/snowpark/_internal/utils.py
@@ -795,7 +795,8 @@ def parse_table_name(table_name: str) -> List[str]:
 
 EMPTY_STRING = ""
 DOUBLE_QUOTE = '"'
-ALREADY_QUOTED = re.compile('^(".+")$')
+# Quoted values may also include newlines, so '.' must match _everything_ within quotes
+ALREADY_QUOTED = re.compile('^(".+")$', re.DOTALL)
 UNQUOTED_CASE_INSENSITIVE = re.compile("^([_A-Za-z]+[_A-Za-z0-9$]*)$")
 
 
diff --git a/tests/integ/test_dataframe.py b/tests/integ/test_dataframe.py
index d9c9dae725e..bf746e66258 100644
--- a/tests/integ/test_dataframe.py
+++ b/tests/integ/test_dataframe.py
@@ -1958,6 +1958,7 @@ def test_case_insensitive_collect(session):
     assert row["p@$$w0rd"] == "test"
     assert row["P@$$W0RD"] == "test"
 
+
 def test_case_insensitive_local_iterator(session):
     df = session.create_dataframe(
         [["Gordon", 153]], schema=["firstname", "matches_won"]
@@ -3322,3 +3323,19 @@ def test_select_star_and_more_columns(session):
     Utils.check_answer(df2, [Row(1, 2, 3)])
     df3 = df2.select("a", "b", "c")
     Utils.check_answer(df3, [Row(1, 2, 3)])
+
+
+def test_drop_columns_special_names(session):
+    """Test whether columns with newlines can be dropped."""
+    table_name = Utils.random_table_name()
+    Utils.create_table(
+        session, table_name, '"a\nb" string, id number', is_temporary=True
+    )
+    session._conn.run_query(f"insert into {table_name} values ('a', 1), ('b', 2)")
+    df = session.table(table_name)
+    try:
+        Utils.check_answer(df, [Row("a", 1), Row("b", 2)])
+        df2 = df.drop('"a\nb"')
+        Utils.check_answer(df2, [Row(1), Row(2)])
+    finally:
+        Utils.drop_table(session, table_name)