Improve resilience of xcode-locator.

LSCopyApplicationURLsForBundleIdentifier rarely will return an
invalid Xcode bundle, which would lead to xcode-locator failure.

To work around this issue, we double check that the given NSBundle
has the same bundleIdentifier as Xcode.

RELNOTES: None.
PiperOrigin-RevId: 214264402

tools/osx/xcode_locator.m

diff --git a/tools/osx/xcode_locator.m b/tools/osx/xcode_locator.m
index e247395..cd44267 100644
--- a/tools/osx/xcode_locator.m
+++ b/tools/osx/xcode_locator.m
@@ -116,13 +116,14 @@
 // and returns nil.
 static NSMutableDictionary<NSString *, XcodeVersionEntry *> *FindXcodes()
   __attribute((ns_returns_retained)) {
-  CFStringRef bundleID = CFSTR("com.apple.dt.Xcode");
+  CFStringRef cfBundleID = CFSTR("com.apple.dt.Xcode");
+  NSString *bundleID = (__bridge NSString *)cfBundleID;
 
   NSMutableDictionary<NSString *, XcodeVersionEntry *> *dict =
       [[NSMutableDictionary alloc] init];
   CFErrorRef cfError;
   NSArray *array = CFBridgingRelease(LSCopyApplicationURLsForBundleIdentifier(
-      bundleID, &cfError));
+      cfBundleID, &cfError));
   if (array == nil) {
     NSError *nsError = (__bridge NSError *)cfError;
     fprintf(stderr, "error: %s\n", nsError.description.UTF8String);
@@ -150,6 +151,19 @@
       continue;
     }
 
+    // LSCopyApplicationURLsForBundleIdentifier seems to sometimes return
+    // invalid bundles (e.g. an arbitrary folder), which we should ignore (but
+    // don't treat as an error).
+    //
+    // To work around this issue, we double check to make sure the NSBundle's
+    // bundleIdentifier is that of Xcode's, as invalid bundles won't match.
+    if (![bundle.bundleIdentifier isEqualToString:bundleID]) {
+      NSLog(@"WARNING: Ignoring bundle %@ due to bundleID mismatch "
+            @"(got \"%@\" but expected \"%@\"); info: %@",
+            url, bundle.bundleIdentifier, bundleID, bundle.infoDictionary);
+      continue;
+    }
+
     NSString *versionKey = @"CFBundleShortVersionString";
     NSString *version = [bundle.infoDictionary objectForKey:versionKey];
     if (version == nil) {