Wait for create_ap to exit after AP-ENABLED in UI

[joanbm]

To create a hotspot, the UI launches create_ap with popen and waits for it to print "AP-ENABLED" to confirm the hotspot has been created. When this happens, it immediately returns, without calling pclose.

This not only leaks the FILE * opened by popen, but it can also inadvertently cause create_ap to get terminated:

• The user launches wihotspot-gui as root
• wihotspot-gui launches pkexec --user root create_ap ...
• pkexec sets a SIGTERM parent-death signal via prctl
• pkexec launches create_ap and it starts running
• create_ap creates the hotspot and prints "AP-ENABLED"
• wihotspot-gui updates the UI, and returns without waiting for create_ap to exit
• Immediately after, the init_running_info thread exits
• A SIGTERM parent-death signal is sent to create_ap
• create_ap terminates and the hotspot stops running

(This only reproduces if wihotspot-gui runs as root, likely due to setuid restrictions for prctl applying otherwise)

Wait for create_ap to exit using pclose to fix the problem.

[Copilot]

Pull Request Overview

This PR ensures the UI waits for the create_ap process to finish after detecting "AP-ENABLED", preventing file-pointer leaks and unintended process termination.

• Add a pclose(fp) call immediately after detecting "AP-ENABLED"
• Ensures the popen'd create_ap process is properly reaped

Comments suppressed due to low confidence (1)

src/ui/ui.c:777

• To ensure the FILE * is always closed in every exit path, you might move pclose(fp) into a common cleanup section or after the loop, rather than only before this early return.

            return 0;

[Copilot]

[nitpick] Consider checking the return value of pclose(fp) to detect and handle potential errors when closing the pipe to the create_ap process.

Suggested change

	pclose(fp);
	int pclose_status = pclose(fp);
	if (pclose_status != 0) {
	printf("Error: pclose() failed with status %d\n", pclose_status);
	init_running_info(NULL);
	return NULL;
	}