[geary] Ensure Db.Database corruption check doesn't fail on missing DB file.

[Michael Gratton <mjog src gnome org>]

commit 1b49fc110464a815927df3accb52f3babd6d5dbd
Author: Michael James Gratton <mike vee net>
Date:   Mon May 21 21:01:34 2018 +1000

    Ensure Db.Database corruption check doesn't fail on missing DB file.
    
    * src/engine/db/db-database.vala (Context): Only run the corruption check
      if there is a DB file and the file exists. Add unit tests.

 src/engine/db/db-database.vala       |    4 ++-
 test/engine/db/db-database-test.vala |   51 ++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletions(-)
---
diff --git a/src/engine/db/db-database.vala b/src/engine/db/db-database.vala
index a558ef1..3d3aeb2 100644
--- a/src/engine/db/db-database.vala
+++ b/src/engine/db/db-database.vala
@@ -136,7 +136,9 @@ public class Geary.Db.Database : Geary.Db.Context {
             warning("SQLite not thread-safe: asynchronous queries will not be available");
         }
 
-        if ((flags & DatabaseFlags.CHECK_CORRUPTION) != 0) {
+        if ((flags & DatabaseFlags.CHECK_CORRUPTION) != 0 &&
+            this.file != null &&
+            yield Geary.Files.query_exists_async(this.file, cancellable)) {
             yield Nonblocking.Concurrent.global.schedule_async(() => {
                     check_for_corruption(flags, cancellable);
                 }, cancellable);
diff --git a/test/engine/db/db-database-test.vala b/test/engine/db/db-database-test.vala
index e79e8d4..25b5dda 100644
--- a/test/engine/db/db-database-test.vala
+++ b/test/engine/db/db-database-test.vala
@@ -15,6 +15,8 @@ class Geary.Db.DatabaseTest : TestCase {
         add_test("open_create_file", open_create_file);
         add_test("open_create_dir", open_create_dir);
         add_test("open_create_dir_existing", open_create_dir_existing);
+        add_test("open_check_corruption", open_check_corruption);
+        add_test("open_create_check", open_create_check);
     }
 
     public void transient_open() throws Error {
@@ -121,5 +123,54 @@ class Geary.Db.DatabaseTest : TestCase {
         tmp_dir.delete();
     }
 
+    public void open_check_corruption() throws Error {
+        GLib.File tmp_dir = GLib.File.new_for_path(
+            GLib.DirUtils.make_tmp("geary-db-database-test-XXXXXX")
+        );
+
+        Database db = new Geary.Db.Database.persistent(
+            tmp_dir.get_child("test.db")
+        );
+        db.open.begin(
+            Geary.Db.DatabaseFlags.CREATE_FILE |
+            Geary.Db.DatabaseFlags.CHECK_CORRUPTION,
+            null, null,
+            (obj, ret) => { async_complete(ret); }
+        );
+        db.open.end(async_result());
+
+        // Need to get a connection since the database doesn't
+        // actually get created until then
+        db.get_master_connection();
+
+        db.file.delete();
+        tmp_dir.delete();
+    }
+
+    public void open_create_check() throws Error {
+        GLib.File tmp_dir = GLib.File.new_for_path(
+            GLib.DirUtils.make_tmp("geary-db-database-test-XXXXXX")
+        );
+
+        Database db = new Geary.Db.Database.persistent(
+            tmp_dir.get_child("nonexistent").get_child("test.db")
+        );
+        db.open.begin(
+            Geary.Db.DatabaseFlags.CREATE_DIRECTORY |
+            Geary.Db.DatabaseFlags.CREATE_FILE |
+            Geary.Db.DatabaseFlags.CHECK_CORRUPTION,
+            null, null,
+            (obj, ret) => { async_complete(ret); }
+        );
+        db.open.end(async_result());
+
+        // Need to get a connection since the database doesn't
+        // actually get created until then
+        db.get_master_connection();
+
+        db.file.delete();
+        db.file.get_parent().delete();
+        tmp_dir.delete();
+    }
 
 }