Flutter - Hot restart in console causes iOS Dropbox to crash

[PKiman]

The use of Hot restart function in the console causes Dropbox iOS library to crash.

Related issue:
Hot Restart does not dispose native iOS/Android plugins.
flutter/flutter#69949

Dropbox iOS client library forces app crash:
(Bad software design I think. Should be just a warning.)

NSAssert(![DBOAuthManager sharedOAuthManager], @"Only call `[DBClientsManager setupWith...]` once");

https://github.com/dropbox/dropbox-sdk-obj-c/blob/0d6f0bac2519f1e36b4f9c19c108eb50ca3a59be/Source/ObjectiveDropboxOfficial/Shared/Handwritten/DBClientsManager.m#L104

Steps:

1. Init Dropbox Library via flutter iOS (Simulator/iPhone)
2. Press Shift+R in the console for hot restart the application
   Observed:

*** Assertion failure in +[DBClientsManager setupWithOAuthManager:transportConfig:], DBClientsManager.m:106
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Only call `[DBClientsManager setupWith...]` once'
*** First throw call stack:
(0x195c31e48 0x18eefb8d8 0x1904ea94c 0x1058f6b68 0x1058f86e0 0x1058f85e0 0x102e3eacc 0x109ce276c 0x10973cb80 0x19d2434b4 0x19d244fdc 0x19d2537f4 0x19d253444 0x195cc26d8 0x195ca403c 0x195ca8ec0 0x1cfcff368 0x19819e86c 0x19819e4d0 0x102653e68 0x1b44ca960)
libc++abi: terminating with uncaught exception of type NSException
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00000001d35a3160 libsystem_kernel.dylib`__pthread_kill + 8
libsystem_kernel.dylib`:
->  0x1d35a3160 <+8>:  b.lo   0x1d35a3180               ; <+40>
    0x1d35a3164 <+12>: pacibsp 
    0x1d35a3168 <+16>: stp    x29, x30, [sp, #-0x10]!
    0x1d35a316c <+20>: mov    x29, sp
Target 0: (Runner) stopped.

Solution 1:
check static sharedOAuthManager if it has been initialised already and exit.
file: DropboxPlugin.m

    } else if ([@"init" isEqualToString:call.method]) {
//        NSString *clientId = call.arguments[@"clientId"];
        NSString *key = call.arguments[@"key"];
//        NSString *secret = call.arguments[@"secret"];
        if ([DBOAuthManager sharedOAuthManager]) {
          NSLog(@"Already initialized with appKey %@", appKey);
          result(@(TRUE));
          return;
        }
        appKey = key;

Solution 2:
Remove NSAssert from the dropbox library:
https://github.com/dropbox/dropbox-sdk-obj-c/blob/0d6f0bac2519f1e36b4f9c19c108eb50ca3a59be/Source/ObjectiveDropboxOfficial/Shared/Handwritten/DBClientsManager.m#L104

[PKiman]

Here the related PR
Hot restart works for me.

Can someone review?