Open Radar

 
06-Jun-2013 04:05 PM Matias Piipari:
Summary:

Removing a PDFPage from a PDFDocument with -removePageAtIndex: throws an exception unless all pages for the document have been loaded with -pageAtIndex: before removing the page. 

- Issue is specific to OSX 10.8.4.
- Can be worked around by sending -pageAtIndex: for all of the document's pages from 0..(doc.pageCount - 1) before sending -removePageAtIndex:
- Example application demonstrating the bug and a workaround for it is attached, and can be found from:
https://dl.dropboxusercontent.com/u/511181/PDFPageRemovalBugDemo1084.zip

Steps to Reproduce:

1) Load a PDF document

    PDFDocument *doc =
        [[PDFDocument alloc] initWithURL:
            [[NSBundle mainBundle] URLForResource:@"chicken" withExtension:@"pdf"]];

2) Remove a page from the document

    [doc removePageAtIndex:0]; // causes an exception because -annotations is sent to a __NSCFNumber instance.



Expected Results:

The PDF page at index 0 was removed from the document.



Actual Results:

An unrecognizer selector exception is thrown somewhere inside -removePageAtIndex:

2013-06-06 15:37:33.595 PDFPageRemovalBugDemo1084[57470:303] -[__NSCFNumber annotations]: unrecognized selector sent to instance 0x287

Full stack trace of the thread:

#0	0x00007fff8d6ee3c6 in objc_exception_throw ()
#1	0x00007fff8807540a in -[NSObject(NSObject) doesNotRecognizeSelector:] ()
#2	0x00007fff87fcd02e in ___forwarding___ ()
#3	0x00007fff87fcce18 in _CF_forwarding_prep_0 ()
#4	0x00007fff81f7afde in -[PDFDocument removePageAtIndex:] ()
#5	0x0000000100001319 in -[MTAppDelegate applicationDidFinishLaunching:] at /Users/mz2/Projects/PDFPageRemovalBugDemo1084/PDFPageRemovalBugDemo1084/MTAppDelegate.m:19

The -removePageAtIndex: part of the stack trace:

PDFKit`-[PDFDocument removePageAtIndex:]:
0x7fff81f7ae46:  pushq  %rbp
0x7fff81f7ae47:  movq   %rsp, %rbp
0x7fff81f7ae4a:  pushq  %r15
0x7fff81f7ae4c:  pushq  %r14
0x7fff81f7ae4e:  pushq  %r13
0x7fff81f7ae50:  pushq  %r12
0x7fff81f7ae52:  pushq  %rbx
0x7fff81f7ae53:  subq   $456, %rsp
0x7fff81f7ae5a:  movq   %rdx, %r14
0x7fff81f7ae5d:  movq   %rdi, %rbx
0x7fff81f7ae60:  movq   %rbx, -456(%rbp)
0x7fff81f7ae67:  movq   701450(%rip), %rax
0x7fff81f7ae6e:  movq   (%rax), %rax
0x7fff81f7ae71:  movq   %rax, -48(%rbp)
0x7fff81f7ae75:  movq   844204(%rip), %rax
0x7fff81f7ae7c:  movq   (%rbx,%rax), %rax
0x7fff81f7ae80:  movq   843841(%rip), %rcx
0x7fff81f7ae87:  cmpq   $0, (%rax,%rcx)
0x7fff81f7ae8c:  je     0x7fff81f7b19a            ; -[PDFDocument removePageAtIndex:] + 852
0x7fff81f7ae92:  movq   801399(%rip), %rsi
0x7fff81f7ae99:  movq   %rbx, %rdi
0x7fff81f7ae9c:  callq  *701718(%rip)
0x7fff81f7aea2:  testb  %al, %al
0x7fff81f7aea4:  je     0x7fff81f7aeb6            ; -[PDFDocument removePageAtIndex:] + 112
0x7fff81f7aea6:  movq   801387(%rip), %rsi
0x7fff81f7aead:  movq   %rbx, %rdi
0x7fff81f7aeb0:  callq  *701698(%rip)
0x7fff81f7aeb6:  movq   800963(%rip), %rsi        ; BZ2_hbCreateDecodeTables + 176
0x7fff81f7aebd:  movq   %rbx, %rdi
0x7fff81f7aec0:  movq   %r14, %rdx
0x7fff81f7aec3:  callq  *701679(%rip)
0x7fff81f7aec9:  movq   %rax, %r15
0x7fff81f7aecc:  testq  %r15, %r15
0x7fff81f7aecf:  je     0x7fff81f7aef8            ; -[PDFDocument removePageAtIndex:] + 178
0x7fff81f7aed1:  movq   800040(%rip), %rsi        ; BZ2_hbMakeCodeLengths + 376
0x7fff81f7aed8:  movq   %r15, %rdi
0x7fff81f7aedb:  callq  *701655(%rip)
0x7fff81f7aee1:  cmpq   %rbx, %rax
0x7fff81f7aee4:  jne    0x7fff81f7aef8            ; -[PDFDocument removePageAtIndex:] + 178
0x7fff81f7aee6:  movq   800147(%rip), %rsi        ; BZ2_hbMakeCodeLengths + 504
0x7fff81f7aeed:  movq   %r15, %rdi
0x7fff81f7aef0:  xorl   %edx, %edx
0x7fff81f7aef2:  callq  *701632(%rip)
0x7fff81f7aef8:  movq   844073(%rip), %rax
0x7fff81f7aeff:  movq   (%rbx,%rax), %rax
0x7fff81f7af03:  movq   843710(%rip), %rcx
0x7fff81f7af0a:  movq   (%rax,%rcx), %rdi
0x7fff81f7af0e:  movq   801299(%rip), %rsi
0x7fff81f7af15:  movq   %r14, %rdx
0x7fff81f7af18:  callq  *701594(%rip)
0x7fff81f7af1e:  movq   844035(%rip), %rax
0x7fff81f7af25:  movq   (%rbx,%rax), %rax
0x7fff81f7af29:  xorps  %xmm0, %xmm0
0x7fff81f7af2c:  movq   843829(%rip), %rdi
0x7fff81f7af33:  leaq   813462(%rip), %rsi        ; copyfile_internal + 1235
0x7fff81f7af3a:  leaq   -112(%rbp), %rdx
0x7fff81f7af3e:  leaq   -240(%rbp), %rcx
0x7fff81f7af45:  movq   %r14, (%rax,%rdi)
0x7fff81f7af49:  movaps %xmm0, -64(%rbp)
0x7fff81f7af4d:  movaps %xmm0, -80(%rbp)
0x7fff81f7af51:  movaps %xmm0, -96(%rbp)
0x7fff81f7af55:  movaps %xmm0, -112(%rbp)
0x7fff81f7af59:  movq   843976(%rip), %rax
0x7fff81f7af60:  movq   (%rbx,%rax), %rax
0x7fff81f7af64:  movq   843613(%rip), %rdi
0x7fff81f7af6b:  movq   (%rax,%rdi), %rdi
0x7fff81f7af6f:  movq   %rdi, -472(%rbp)
0x7fff81f7af76:  movl   $16, %r8d
0x7fff81f7af7c:  callq  *813390(%rip)             ; copyfile_internal + 1235
0x7fff81f7af82:  movq   %rax, -480(%rbp)
0x7fff81f7af89:  testq  %rax, %rax
0x7fff81f7af8c:  je     0x7fff81f7b19a            ; -[PDFDocument removePageAtIndex:] + 852
0x7fff81f7af92:  movq   -96(%rbp), %rax
0x7fff81f7af96:  movq   (%rax), %rax
0x7fff81f7af99:  movq   %rax, -488(%rbp)
0x7fff81f7afa0:  movq   701457(%rip), %r14
0x7fff81f7afa7:  xorl   %ebx, %ebx
0x7fff81f7afa9:  movq   -96(%rbp), %rax
0x7fff81f7afad:  movq   -488(%rbp), %rcx
0x7fff81f7afb4:  cmpq   %rcx, (%rax)
0x7fff81f7afb7:  je     0x7fff81f7afc5            ; -[PDFDocument removePageAtIndex:] + 383
0x7fff81f7afb9:  movq   -472(%rbp), %rdi
0x7fff81f7afc0:  callq  0x7fff81ffa068            ; symbol stub for: objc_enumerationMutation
0x7fff81f7afc5:  movq   -104(%rbp), %rax
0x7fff81f7afc9:  movq   (%rax,%rbx,8), %rdi
0x7fff81f7afcd:  movq   %rbx, -464(%rbp)
0x7fff81f7afd4:  movq   800541(%rip), %rsi        ; BZ2_hbCreateDecodeTables + 40
0x7fff81f7afdb:  callq  *%r14
0x7fff81f7afde:  movq   %rax, %rdi
0x7fff81f7afe1:  movq   800464(%rip), %rbx        ; BZ2_hbAssignCodes + 39
0x7fff81f7afe8:  movq   %rbx, %rsi
0x7fff81f7afeb:  callq  *%r14
0x7fff81f7afee:  xorps  %xmm0, %xmm0
0x7fff81f7aff1:  movaps %xmm0, -256(%rbp)
0x7fff81f7aff8:  movaps %xmm0, -272(%rbp)
0x7fff81f7afff:  movaps %xmm0, -288(%rbp)
0x7fff81f7b006:  movaps %xmm0, -304(%rbp)
0x7fff81f7b00d:  movq   %rax, %rdi
0x7fff81f7b010:  movq   %rbx, %rsi
0x7fff81f7b013:  callq  *%r14
0x7fff81f7b016:  movq   %rax, -440(%rbp)
0x7fff81f7b01d:  movq   %rax, %rdi
0x7fff81f7b020:  leaq   813225(%rip), %rsi        ; copyfile_internal + 1235
0x7fff81f7b027:  leaq   -304(%rbp), %rdx
0x7fff81f7b02e:  leaq   -432(%rbp), %rcx
0x7fff81f7b035:  movl   $16, %r8d
0x7fff81f7b03b:  callq  *813199(%rip)             ; copyfile_internal + 1235
0x7fff81f7b041:  movq   %rax, %r12
0x7fff81f7b044:  testq  %r12, %r12
0x7fff81f7b047:  je     0x7fff81f7b14e            ; -[PDFDocument removePageAtIndex:] + 776
0x7fff81f7b04d:  movq   -288(%rbp), %rax
0x7fff81f7b054:  movq   (%rax), %rax
0x7fff81f7b057:  movq   %rax, -448(%rbp)
0x7fff81f7b05e:  xorl   %r15d, %r15d
0x7fff81f7b061:  movq   -288(%rbp), %rax
0x7fff81f7b068:  movq   -448(%rbp), %rcx
0x7fff81f7b06f:  cmpq   %rcx, (%rax)
0x7fff81f7b072:  je     0x7fff81f7b080            ; -[PDFDocument removePageAtIndex:] + 570
0x7fff81f7b074:  movq   -440(%rbp), %rdi
0x7fff81f7b07b:  callq  0x7fff81ffa068            ; symbol stub for: objc_enumerationMutation
0x7fff81f7b080:  movq   -296(%rbp), %rax
0x7fff81f7b087:  movq   (%rax,%r15,8), %r13
0x7fff81f7b08b:  movq   813654(%rip), %rdi        ; copyfile_internal + 1771
0x7fff81f7b092:  leaq   813287(%rip), %rsi        ; copyfile_internal + 1411
0x7fff81f7b099:  callq  *813281(%rip)             ; copyfile_internal + 1411
0x7fff81f7b09f:  leaq   813306(%rip), %rsi        ; copyfile_internal + 1443
0x7fff81f7b0a6:  movq   %r13, %rdi
0x7fff81f7b0a9:  movq   %rax, %rdx
0x7fff81f7b0ac:  callq  *813294(%rip)             ; copyfile_internal + 1443
0x7fff81f7b0b2:  testb  %al, %al
0x7fff81f7b0b4:  je     0x7fff81f7b10e            ; -[PDFDocument removePageAtIndex:] + 712
0x7fff81f7b0b6:  movq   %r13, %rdi
0x7fff81f7b0b9:  movq   800880(%rip), %rsi
0x7fff81f7b0c0:  callq  *%r14
0x7fff81f7b0c3:  movq   %rax, %rdi
0x7fff81f7b0c6:  movq   800251(%rip), %rsi        ; BZ2_hbAssignCodes + 55
0x7fff81f7b0cd:  callq  *%r14
0x7fff81f7b0d0:  movq   %rax, %rdi
0x7fff81f7b0d3:  callq  0x7fff81ffa4dc            ; symbol stub for: CGPDFPageGetPageNumber
0x7fff81f7b0d8:  movq   %rax, %rbx
0x7fff81f7b0db:  movq   -456(%rbp), %rdi
0x7fff81f7b0e2:  movq   800527(%rip), %rsi        ; BZ2_hbCreateDecodeTables + 296
0x7fff81f7b0e9:  callq  *%r14
0x7fff81f7b0ec:  cmpq   %rax, %rbx
0x7fff81f7b0ef:  jbe    0x7fff81f7b10e            ; -[PDFDocument removePageAtIndex:] + 712
0x7fff81f7b0f1:  movq   %r13, %rdi
0x7fff81f7b0f4:  movq   800821(%rip), %rsi
0x7fff81f7b0fb:  callq  *%r14
0x7fff81f7b0fe:  movq   %rax, %rdi
0x7fff81f7b101:  movq   800816(%rip), %rsi
0x7fff81f7b108:  movq   %r13, %rdx
0x7fff81f7b10b:  callq  *%r14
0x7fff81f7b10e:  incq   %r15
0x7fff81f7b111:  cmpq   %r12, %r15
0x7fff81f7b114:  jb     0x7fff81f7b061            ; -[PDFDocument removePageAtIndex:] + 539
0x7fff81f7b11a:  movq   -440(%rbp), %rdi
0x7fff81f7b121:  leaq   812968(%rip), %rsi        ; copyfile_internal + 1235
0x7fff81f7b128:  leaq   -304(%rbp), %rdx
0x7fff81f7b12f:  leaq   -432(%rbp), %rcx
0x7fff81f7b136:  movl   $16, %r8d
0x7fff81f7b13c:  callq  *812942(%rip)             ; copyfile_internal + 1235
0x7fff81f7b142:  movq   %rax, %r12
0x7fff81f7b145:  testq  %r12, %r12
0x7fff81f7b148:  jne    0x7fff81f7b05e            ; -[PDFDocument removePageAtIndex:] + 536
0x7fff81f7b14e:  movq   -464(%rbp), %rbx
0x7fff81f7b155:  incq   %rbx
0x7fff81f7b158:  cmpq   -480(%rbp), %rbx
0x7fff81f7b15f:  jb     0x7fff81f7afa9            ; -[PDFDocument removePageAtIndex:] + 355
0x7fff81f7b165:  movq   -472(%rbp), %rdi
0x7fff81f7b16c:  leaq   812893(%rip), %rsi        ; copyfile_internal + 1235
0x7fff81f7b173:  leaq   -112(%rbp), %rdx
0x7fff81f7b177:  leaq   -240(%rbp), %rcx
0x7fff81f7b17e:  movl   $16, %r8d
0x7fff81f7b184:  callq  *812870(%rip)             ; copyfile_internal + 1235
0x7fff81f7b18a:  movq   %rax, -480(%rbp)
0x7fff81f7b191:  testq  %rax, %rax
0x7fff81f7b194:  jne    0x7fff81f7afa7            ; -[PDFDocument removePageAtIndex:] + 353
0x7fff81f7b19a:  movq   700631(%rip), %rax
0x7fff81f7b1a1:  movq   (%rax), %rax
0x7fff81f7b1a4:  cmpq   -48(%rbp), %rax
0x7fff81f7b1a8:  jne    0x7fff81f7b1bc            ; -[PDFDocument removePageAtIndex:] + 886
0x7fff81f7b1aa:  addq   $456, %rsp
0x7fff81f7b1b1:  popq   %rbx
0x7fff81f7b1b2:  popq   %r12
0x7fff81f7b1b4:  popq   %r13
0x7fff81f7b1b6:  popq   %r14
0x7fff81f7b1b8:  popq   %r15
0x7fff81f7b1ba:  popq   %rbp
0x7fff81f7b1bb:  ret    
0x7fff81f7b1bc:  callq  0x7fff81ff9eca            ; symbol stub for: __stack_chk_fail



Notes:

It is possible to work around the issue by forcing the loading of pages for the document before removing the page. The following code does *not* cause an exception to be thrown:

    PDFDocument *doc =
        [[PDFDocument alloc] initWithURL:
            [[NSBundle mainBundle] URLForResource:@"chicken" withExtension:@"pdf"]];
    
    // forcing the loading of document's pages suppresses the exception throwing 
    for (NSUInteger i = 0, pageCount = doc.pageCount; i < pageCount; i++)
        [doc pageAtIndex:i];
    
    [doc removePageAtIndex:0];

Working around the issue requires loading *all* pages, for instance the following does *not* suppress the error:

    for (NSUInteger i = 0, pageCount = (doc.pageCount - 1); i < pageCount; i++)
        [doc pageAtIndex:i];
    
Inspecting the call stack above, and the class-dumped headers of PDFKit.framework suggests the issue has something to do with how the _pdfPriv->pageArray of a PDFDocument contains pages that have not yet been loaded as NSNumber instances (numbers contain the page number?), not PDFPage instances.

06-Jun-2013 04:05 PM Matias Piipari:
'PDFPageRemovalBugDemo1084.zip' was successfully uploaded