Clear signals after running initial commands

If you run an initial command via `fish -c`, and that command is
cancelled e.g. via control-C, then ensure that the cancellation signal
is cleared before running config files.

Fixes #9024

CHANGELOG.rst

@@ -13,6 +13,7 @@ Scripting improvements
 
 Interactive improvements
 ------------------------
+- Cancelling an initial command via control-C no longer prevents configuration scripts from running (:issue:`9024`).
 
 New or improved bindings
 ^^^^^^^^^^^^^^^^^^^^^^^^

src/fish.cpp

@@ -545,6 +545,9 @@ int main(int argc, char **argv) {
         res = run_command_list(parser, opts.postconfig_cmds, {});
     }
 
+    // Clear signals in case we were interrupted (#9024).
+    signal_clear_cancel();
+
     if (!opts.batch_cmds.empty()) {
         // Run the commands specified as arguments, if any.
         if (get_login()) {