Re-think disk full handling

Instead of trying to inform the sysadmin (which we did not yet try to
do in any meaningful way), inform all connected clients (even those
editing other documents).

We use 'error: cmd=internal kind=diskfull' as the message to the
clients. The loleaflet code needs to be updated to handle that
carefully by displaying a very prominent message that tells the user
that all bets are off.

Also add a unit test for the functionality.

Document the new protocol details.

The code for this alert functionalty became a bit less elegant than I
like because of the way we include Util.cpp in the unit test 'test'
program.

Still need to add code to check for disk full in more places, not just
when saving a cached tile or font. Probably we should even actually
check for disk space on the file system(s) we use getting alarmingly
low, not just check for file writing operations that fail. Later.

1 files changed, 11 insertions, 0 deletions

diff --git a/loolwsd/LOKitClient.cpp b/loolwsd/LOKitClient.cpp
index b882b7968..06d0a3333 100644
--- a/loolwsd/LOKitClient.cpp
+++ b/loolwsd/LOKitClient.cpp
@@ -206,6 +206,17 @@ protected:
     }
 };
 
+namespace Util
+{
+
+void alertAllUsers(const std::string& cmd, const std::string& kind)
+{
+    std::cout << "error: cmd=" << cmd << " kind=" << kind << std::endl;
+    (void) kind;
+}
+
+}
+
 POCO_APP_MAIN(LOKitClient)
 
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