Improve robustness of database name parsing in dbbackup command (#600)

- Enhanced `_get_database_keys()` method to filter empty strings and strip whitespace

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Archmonger <16909269+Archmonger@users.noreply.github.com>

Author: Copilot

.gitattributes

@@ -0,0 +1 @@
+* text=auto eol=lf

.github/copilot-instructions.md

@@ -6,6 +6,8 @@ Always reference these instructions first and fallback to search or bash command
 
 **IMPORTANT**: This package has been fully migrated to modern Python tooling using Hatch. Always use Hatch commands for development workflows.
 
+**BUG INVESTIGATION**: When investigating whether a bug was already resolved in a previous version, always prioritize searching through `CHANGELOG.md` first before using Git history. Only search through Git history when no relevant changelog entries are found.
+
 ## Working Effectively
 
 Bootstrap, build, and test the repository:

CHANGELOG.md

@@ -31,6 +31,7 @@ Don't forget to remove deprecated code on each major release!
 
 ### Fixed
 
+- Fix issues with parsing excess whitespace within `dbbackup -d "<COMMA_SEPARATED_ARGS>"`
 - Fix encryption support when using `gnupg==5.x`.
 - Resolve SQLite backup temporary file locking issues on Windows.
 

dbbackup/management/commands/dbbackup.py

@@ -26,8 +26,7 @@ class Command(BaseDbBackupCommand):
         make_option(
             "-d",
             "--database",
-            help="Database(s) to backup specified by key separated by"
-            " commas(default: all)",
+            help="Database(s) to backup specified by key separated by commas(default: all)",
         ),
         make_option(
             "-s",
@@ -48,18 +47,14 @@ class Command(BaseDbBackupCommand):
             default=False,
             help="Encrypt the backup files",
         ),
-        make_option(
-            "-o", "--output-filename", default=None, help="Specify filename on storage"
-        ),
+        make_option("-o", "--output-filename", default=None, help="Specify filename on storage"),
         make_option(
             "-O",
             "--output-path",
             default=None,
             help="Specify where to store on local filesystem",
         ),
-        make_option(
-            "-x", "--exclude-tables", default=None, help="Exclude tables from backup"
-        ),
+        make_option("-x", "--exclude-tables", default=None, help="Exclude tables from backup"),
         make_option(
             "-n",
             "--schema",
@@ -92,9 +87,7 @@ def handle(self, **options):
         for database_key in self._get_database_keys():
             self.connector = get_connector(database_key)
             if self.connector and self.exclude_tables:
-                self.connector.exclude.extend(
-                    list(self.exclude_tables.replace(" ", "").split(","))
-                )
+                self.connector.exclude.extend(list(self.exclude_tables.replace(" ", "").split(",")))
             database = self.connector.settings
             try:
                 self._save_new_backup(database)
@@ -104,7 +97,18 @@ def handle(self, **options):
                 raise CommandError(err) from err
 
     def _get_database_keys(self):
-        return self.database.split(",") if self.database else settings.DATABASES
+        """
+        Get the list of database keys to backup.
+
+        Returns the databases specified by the -d/--database option,
+        or falls back to the DBBACKUP_DATABASES setting if no option is provided.
+        """
+        if self.database:
+            # Split by comma and filter out empty strings to prevent
+            # get_connector('') from being called, which would fall back
+            # to the 'default' database and ignore DBBACKUP_DATABASES
+            return [key.strip() for key in self.database.split(",") if key.strip()]
+        return settings.DATABASES
 
     def _save_new_backup(self, database):
         """

docs/src/dictionary.txt

@@ -39,3 +39,4 @@ config
 dumpable
 schemas
 redistributions
+whitespace

pyproject.toml

@@ -221,9 +221,9 @@ lint.extend-ignore = []
 addopts = ["--strict-config", "--strict-markers"]
 
 [tool.coverage]
-paths.source = ["dbbackup"]
 run.relative_files = true
 run.branch = true
 run.parallel = true
 run.source = ["dbbackup/"]
+paths.source = ["dbbackup/"]
 report.show_missing = true

tests/commands/test_dbbackup.py

@@ -74,6 +74,26 @@ def test_get_database_keys(self):
             self.command.database = ""
             self.assertEqual(self.command._get_database_keys(), ["db-from-settings"])
 
+        with self.subTest("multiple databases"):
+            self.command.database = "db1,db2"
+            self.assertEqual(self.command._get_database_keys(), ["db1", "db2"])
+
+        with self.subTest("multiple databases with whitespace"):
+            self.command.database = " db1 , db2 "
+            self.assertEqual(self.command._get_database_keys(), ["db1", "db2"])
+
+        with self.subTest("filter out empty strings to prevent get_connector('') bug"):
+            self.command.database = "db1,,db2"
+            self.assertEqual(self.command._get_database_keys(), ["db1", "db2"])
+
+        with self.subTest("just comma returns empty list"):
+            self.command.database = ","
+            self.assertEqual(self.command._get_database_keys(), [])
+
+        with self.subTest("just spaces returns empty list"):
+            self.command.database = "  "
+            self.assertEqual(self.command._get_database_keys(), [])
+
 
 @patch("dbbackup.settings.GPG_RECIPIENT", "test@test")
 @patch("sys.stdout", DEV_NULL)