From 27759a12c74b62b82b33e4661ccc74572fb6597a Mon Sep 17 00:00:00 2001
From: Ryan Leckey <ryan@launchbadge.com>
Date: Mon, 30 Dec 2019 01:31:01 -0800
Subject: [PATCH] [MySQL] Allow not specifying database on initial connect

---
 sqlx-core/src/mysql/connection.rs                  | 13 +++++++------
 sqlx-core/src/mysql/protocol/handshake_response.rs |  8 +++++---
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/sqlx-core/src/mysql/connection.rs b/sqlx-core/src/mysql/connection.rs
index 87197010..0592cd1f 100644
--- a/sqlx-core/src/mysql/connection.rs
+++ b/sqlx-core/src/mysql/connection.rs
@@ -152,10 +152,12 @@ impl MySqlConnection {
         let handshake_packet = self_.receive().await?;
         let handshake = Handshake::decode(handshake_packet)?;
 
-        let client_capabilities = Capabilities::PROTOCOL_41
-            | Capabilities::IGNORE_SPACE
-            | Capabilities::FOUND_ROWS
-            | Capabilities::CONNECT_WITH_DB;
+        let mut client_capabilities =
+            Capabilities::PROTOCOL_41 | Capabilities::IGNORE_SPACE | Capabilities::FOUND_ROWS;
+
+        if url.database().is_some() {
+            client_capabilities |= Capabilities::CONNECT_WITH_DB;
+        }
 
         // Fails if [Capabilities::PROTOCOL_41] is not in [server_capabilities]
         self_.capabilities =
@@ -167,8 +169,7 @@ impl MySqlConnection {
             client_collation: 192, // utf8_unicode_ci
             max_packet_size: 1024,
             username: url.username().unwrap_or("root"),
-            // TODO: Remove the panic!
-            database: url.database().expect("required database"),
+            database: url.database(),
             auth_plugin_name: handshake.auth_plugin_name.as_deref(),
             auth_response: None,
         });
diff --git a/sqlx-core/src/mysql/protocol/handshake_response.rs b/sqlx-core/src/mysql/protocol/handshake_response.rs
index 4bb1f14b..78851590 100644
--- a/sqlx-core/src/mysql/protocol/handshake_response.rs
+++ b/sqlx-core/src/mysql/protocol/handshake_response.rs
@@ -11,7 +11,7 @@ pub struct HandshakeResponse<'a> {
     pub max_packet_size: u32,
     pub client_collation: u8,
     pub username: &'a str,
-    pub database: &'a str,
+    pub database: Option<&'a str>,
     pub auth_plugin_name: Option<&'a str>,
     pub auth_response: Option<&'a str>,
 }
@@ -55,8 +55,10 @@ impl Encode for HandshakeResponse<'_> {
         }
 
         if capabilities.contains(Capabilities::CONNECT_WITH_DB) {
-            // database : string<NUL>
-            buf.put_str_nul(self.database);
+            if let Some(database) = self.database {
+                // database : string<NUL>
+                buf.put_str_nul(database);
+            }
         }
 
         if capabilities.contains(Capabilities::PLUGIN_AUTH) {