From 1660826444554bb4e99c1b15d9e229f22bdfe8d0 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 6 Oct 2025 16:32:09 +0100
Subject: [PATCH 1/4] Fix CREATE TABLE regex to handle IF NOT EXISTS

---
 scripts-dev/check_schema_delta.py | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/scripts-dev/check_schema_delta.py b/scripts-dev/check_schema_delta.py
index 454784c3ae9..ebde5b8b20c 100755
--- a/scripts-dev/check_schema_delta.py
+++ b/scripts-dev/check_schema_delta.py
@@ -11,9 +11,13 @@
 import git
 
 SCHEMA_FILE_REGEX = re.compile(r"^synapse/storage/schema/(.*)/delta/(.*)/(.*)$")
-INDEX_CREATION_REGEX = re.compile(r"CREATE .*INDEX .*ON ([a-z_]+)", flags=re.IGNORECASE)
-INDEX_DELETION_REGEX = re.compile(r"DROP .*INDEX ([a-z_]+)", flags=re.IGNORECASE)
-TABLE_CREATION_REGEX = re.compile(r"CREATE .*TABLE ([a-z_]+)", flags=re.IGNORECASE)
+INDEX_CREATION_REGEX = re.compile(
+    r"CREATE .*INDEX .*ON ([a-z_0-9]+)", flags=re.IGNORECASE
+)
+INDEX_DELETION_REGEX = re.compile(r"DROP .*INDEX ([a-z_0-9]+)", flags=re.IGNORECASE)
+TABLE_CREATION_REGEX = re.compile(
+    r"CREATE .*TABLE.* ([a-z_0-9]+)\s*\(", flags=re.IGNORECASE
+)
 
 # The base branch we want to check against. We use the main development branch
 # on the assumption that is what we are developing against.

From f9003c89f0df598f30be5d5af53f90467c9314d6 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 6 Oct 2025 16:34:13 +0100
Subject: [PATCH 2/4] Test schema file

---
 .../storage/schema/main/delta/92/00_test1.sql | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 synapse/storage/schema/main/delta/92/00_test1.sql

diff --git a/synapse/storage/schema/main/delta/92/00_test1.sql b/synapse/storage/schema/main/delta/92/00_test1.sql
new file mode 100644
index 00000000000..55b64752d7a
--- /dev/null
+++ b/synapse/storage/schema/main/delta/92/00_test1.sql
@@ -0,0 +1,20 @@
+CREATE TABLE test1 (
+    id INT
+);
+
+CREATE INDEX test1_id_idx ON test1 (id);
+
+CREATE TABLE IF NOT EXISTS test2 (
+    id INT
+);
+
+CREATE INDEX test2_id_idx ON test2 (id);
+CREATE INDEX IF NOT EXISTS test2_id_idx ON test2 (id);
+
+CREATE INDEX CONCURRENTLY IF NOT EXISTS test3_id_idx ON test3 (id);
+
+CREATE TEMPORARY TABLE IF NOT EXSTS test4 (
+    id INT
+);
+
+CREATE INDEX IF NOT EXISTS test4_id_idx ON test4 (id);

From 2688f8b7a97ee9f1336c905fbf20f492d6944afe Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 6 Oct 2025 16:48:33 +0100
Subject: [PATCH 3/4] Better diagnostics

---
 scripts-dev/check_schema_delta.py                 | 10 ++++++++--
 synapse/storage/schema/main/delta/92/00_test1.sql |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/scripts-dev/check_schema_delta.py b/scripts-dev/check_schema_delta.py
index ebde5b8b20c..601089cd3a3 100755
--- a/scripts-dev/check_schema_delta.py
+++ b/scripts-dev/check_schema_delta.py
@@ -177,11 +177,14 @@ def main(force_colors: bool) -> None:
                 clause = match.group()
 
                 click.secho(
-                    f"Found delta with index deletion: '{clause}' in {delta_file}\nThese should be in background updates.",
+                    f"Found delta with index deletion: '{clause}' in {delta_file}",
                     fg="red",
                     bold=True,
                     color=force_colors,
                 )
+                click.secho(
+                    " ↪ These should be in background updates.",
+                )
                 return_code = 1
 
             # Check for index creation, which is only allowed for tables we've
@@ -192,11 +195,14 @@ def main(force_colors: bool) -> None:
                 table_name = match.group(1)
                 if table_name not in created_tables:
                     click.secho(
-                        f"Found delta with index creation: '{clause}' in {delta_file}\nThese should be in background updates.",
+                        f"Found delta with index creation for existing table: '{clause}' in {delta_file}",
                         fg="red",
                         bold=True,
                         color=force_colors,
                     )
+                    click.secho(
+                        " ↪ These should be in background updates (or the table should be created in the same delta).",
+                    )
                     return_code = 1
 
     click.get_current_context().exit(return_code)
diff --git a/synapse/storage/schema/main/delta/92/00_test1.sql b/synapse/storage/schema/main/delta/92/00_test1.sql
index 55b64752d7a..abe806ce0d7 100644
--- a/synapse/storage/schema/main/delta/92/00_test1.sql
+++ b/synapse/storage/schema/main/delta/92/00_test1.sql
@@ -13,7 +13,7 @@ CREATE INDEX IF NOT EXISTS test2_id_idx ON test2 (id);
 
 CREATE INDEX CONCURRENTLY IF NOT EXISTS test3_id_idx ON test3 (id);
 
-CREATE TEMPORARY TABLE IF NOT EXSTS test4 (
+CREATE TEMPORARY TABLE IF NOT EXISTS test4 (
     id INT
 );
 

From b767d627c76baae0fee76f51108849c25504d8b8 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Mon, 6 Oct 2025 16:50:40 +0100
Subject: [PATCH 4/4] Newsfile

---
 changelog.d/19020.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/19020.misc

diff --git a/changelog.d/19020.misc b/changelog.d/19020.misc
new file mode 100644
index 00000000000..f5775ff194d
--- /dev/null
+++ b/changelog.d/19020.misc
@@ -0,0 +1 @@
+Fix CI linter for schema delta files to correctly handle all types of `CREATE TABLE` syntax.