Open Radar

 
Summary:
Typing some malformed URI sequence which the data detector mechanism fails to handle gracefully causes almost any application to hang or quit unexpectedly.

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Steps to Reproduce:
1. Activate TextEdit and ⌘N, or activate Mail and ⌘N, or activate Stickies and ⌘N, or open just about any application that allows you to type things, even the search box in Preview, Finder, iTunes, Aperture
2. Type exactly "File:///" followed by enter. The letter F needs to be capital and there should be three slashes following the colon.

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Expected Results:
Application processes this string normally, either doing nothing or perform a search, depending on where this string is typed.

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Actual Results:
Application hangs or quits unexpectedly, creating several entries in system log, for example:
assertion on /SourceCache/DataDetectorsCore/DataDetectorsCore-269.1/Sources/PushDown/DDResultExtraction.c:1576 "CFStringHasPrefix(urlVal, CFSTR("file://"))" failed :wrong extraction: File:///
wrong extraction: File:///
An uncaught exception was raised
condition "wrong extraction: File:///"
[ call stack ]

Sometimes this also leads to data loss/inconsistency, for example Aperture detected library inconsistency on second launch.

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Regression:
In certain circumstances some applications do not exhibit this behaviour, including Pages, Keynote, Numbers. (This only applies to typing the string into the main area. Press ⌘F then type the string into the "Find" textbox will also result in a crash.)
Other applications that provide its own mechanism for text input are also unaffected, such as Terminal, Mathematica, Emacs, MacVim, Microsoft Word.

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Notes:
Due to this bug, filing a bug report is extremely difficult. For example, Safari would hang when I type the string into this textbox. Even merely opening the crash log in Console causes Console to crash.

In crash logs for some applications, DDCrashv is not mentioned but -[NSTextCheckingOperation dealloc] is mentioned.

The data detectors are ostensibly activated by spell checking, therefore disabling data detectors does not seem to work.