Fixed #4680 -- Improved initial_sql parsing

In particular, allow the '--' sequence to be present in string
values without being interpreted as comment marker.
Thanks Tim Chase for the report and shaleh for the initial patch.

django/core/management/sql.py

@@ -136,6 +136,20 @@ def sql_all(app, style, connection):
     "Returns a list of CREATE TABLE SQL, initial-data inserts, and CREATE INDEX SQL for the given module."
     return sql_create(app, style, connection) + sql_custom(app, style, connection) + sql_indexes(app, style, connection)
 
+def _split_statements(content):
+    comment_re = re.compile(r"^((?:'[^']*'|[^'])*?)--.*$")
+    statements = []
+    statement = ""
+    for line in content.split("\n"):
+        cleaned_line = comment_re.sub(r"\1", line).strip()
+        if not cleaned_line:
+            continue
+        statement += cleaned_line
+        if statement.endswith(";"):
+            statements.append(statement)
+            statement = ""
+    return statements
+
 def custom_sql_for_model(model, style, connection):
     opts = model._meta
     app_dir = os.path.normpath(os.path.join(os.path.dirname(models.get_app(model._meta.app_label).__file__), 'sql'))
@@ -149,10 +163,6 @@ def custom_sql_for_model(model, style, connection):
         for f in post_sql_fields:
             output.extend(f.post_create_sql(style, model._meta.db_table))
 
-    # Some backends can't execute more than one SQL statement at a time,
-    # so split into separate statements.
-    statements = re.compile(r";[ \t]*$", re.M)
-
     # Find custom SQL, if it's available.
     backend_name = connection.settings_dict['ENGINE'].split('.')[-1]
     sql_files = [os.path.join(app_dir, "%s.%s.sql" % (opts.object_name.lower(), backend_name)),
@@ -160,12 +170,9 @@ def custom_sql_for_model(model, style, connection):
     for sql_file in sql_files:
         if os.path.exists(sql_file):
             with open(sql_file, 'U') as fp:
-                for statement in statements.split(fp.read().decode(settings.FILE_CHARSET)):
-                    # Remove any comments from the file
-                    statement = re.sub(r"--.*([\n\Z]|$)", "", statement)
-                    if statement.strip():
-                        output.append(statement + ";")
-
+                # Some backends can't execute more than one SQL statement at a time,
+                # so split into separate statements.
+                output.extend(_split_statements(fp.read().decode(settings.FILE_CHARSET)))
     return output
 
 

tests/regressiontests/initial_sql_regress/sql/simple.sql

@@ -1,4 +1,6 @@
-INSERT INTO initial_sql_regress_simple (name) VALUES ('John');
+-- a comment
+INSERT INTO initial_sql_regress_simple (name) VALUES ('John'); -- another comment
+INSERT INTO initial_sql_regress_simple (name) VALUES ('-- Comment Man');
 INSERT INTO initial_sql_regress_simple (name) VALUES ('Paul');
 INSERT INTO initial_sql_regress_simple (name) VALUES ('Ringo');
 INSERT INTO initial_sql_regress_simple (name) VALUES ('George');

tests/regressiontests/initial_sql_regress/tests.py

@@ -4,12 +4,26 @@ from .models import Simple
 
 
 class InitialSQLTests(TestCase):
-    def test_initial_sql(self):
     # The format of the included SQL file for this test suite is important.
     # It must end with a trailing newline in order to test the fix for #2161.
 
-        # However, as pointed out by #14661, test data loaded by custom SQL
+    def test_initial_sql(self):
+        # As pointed out by #14661, test data loaded by custom SQL
         # can't be relied upon; as a result, the test framework flushes the
         # data contents before every test. This test validates that this has
         # occurred.
         self.assertEqual(Simple.objects.count(), 0)
+
+    def test_custom_sql(self):
+        from django.core.management.sql import custom_sql_for_model
+        from django.core.management.color import no_style
+        from django.db import connections, DEFAULT_DB_ALIAS
+
+        # Simulate the custom SQL loading by syncdb
+        connection = connections[DEFAULT_DB_ALIAS]
+        custom_sql = custom_sql_for_model(Simple, no_style(), connection)
+        self.assertEqual(len(custom_sql), 8)
+        cursor = connection.cursor()
+        for sql in custom_sql:
+            cursor.execute(sql)
+        self.assertEqual(Simple.objects.count(), 8)