Bug #14421
Updated by rusterholz (Andy Rusterholz) about 7 years ago
The line of code below causes a segfault on 2.5.0. This appears to possibly be related to #[[11419]], [[#11419]], but is not the same. The segfault is not limited to the String class used in the example; it can be reproduced with any class with at least one instance_method. More generally, it can be reproduced any time `super_method` is called on a Method which was formed by (validly) calling `bind` on an UnboundMethod. ~~~ $ ruby -e 'String.instance_method(:length).bind(String.new).super_method' -e:1: [BUG] Segmentation fault at 0x0000000000000018 ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-darwin17] -- Crash Report log information -------------------------------------------- See Crash Report log file under the one of following: * ~/Library/Logs/DiagnosticReports * /Library/Logs/DiagnosticReports for more details. Don't forget to include the above Crash Report log file in bug reports. -- Control frame information ----------------------------------------------- c:0003 p:---- s:0010 e:000009 CFUNC :super_method c:0002 p:0028 s:0006 e:000005 EVAL -e:1 [FINISH] c:0001 p:0000 s:0003 E:001570 (none) [FINISH] -- Ruby level backtrace information ---------------------------------------- -e:1:in `<main>' -e:1:in `super_method' -- Machine register context ------------------------------------------------ rax: 0x0000000000000000 rbx: 0x00007fc51f43e1e0 rcx: 0x0000000108308730 rdx: 0x0000000000000000 rdi: 0x00007fc52106fd18 rsi: 0x0000000108308730 rbp: 0x00007ffee7b78f80 rsp: 0x00007ffee7b78f40 r8: 0x00007fc51f4623b8 r9: 0x0000000108543fa0 r10: 0x00007fc51f5070e8 r11: 0x0000000000000016 r12: 0x0000000000000000 r13: 0x00007fc51f541860 r14: 0x0000000000000000 r15: 0x00007fc52106fd18 rip: 0x000000010819a2eb rfl: 0x0000000000010246 -- C level backtrace information ------------------------------------------- 0 libruby.2.5.dylib 0x0000000108274d17 rb_vm_bugreport + 135 1 libruby.2.5.dylib 0x00000001080f9988 rb_bug_context + 472 2 libruby.2.5.dylib 0x00000001081e9161 sigsegv + 81 3 libsystem_platform.dylib 0x00007fff7e2c0f5a _sigtramp + 26 4 libruby.2.5.dylib 0x000000010819a2eb method_super_method + 43 5 libruby.2.5.dylib 0x00000001082681fb vm_call_cfunc + 283 6 libruby.2.5.dylib 0x0000000108251954 vm_exec_core + 12196 7 libruby.2.5.dylib 0x0000000108262ace vm_exec + 142 8 libruby.2.5.dylib 0x0000000108103501 ruby_exec_internal + 177 9 libruby.2.5.dylib 0x00000001081033f8 ruby_run_node + 56 10 ruby 0x0000000108086f2f main + 79 -- Other runtime information ----------------------------------------------- * Loaded script: -e * Loaded features: 0 enumerator.so 1 thread.rb 2 rational.so 3 complex.so 4 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/x86_64-darwin17/enc/encdb.bundle 5 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/x86_64-darwin17/enc/trans/transdb.bundle 6 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/x86_64-darwin17/rbconfig.rb 7 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/compatibility.rb 8 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/defaults.rb 9 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/deprecate.rb 10 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/errors.rb 11 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/version.rb 12 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/requirement.rb 13 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/platform.rb 14 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/basic_specification.rb 15 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/stub_specification.rb 16 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/util/list.rb 17 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/x86_64-darwin17/stringio.bundle 18 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/specification.rb 19 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/exceptions.rb 20 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/dependency.rb 21 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/core_ext/kernel_gem.rb 22 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/monitor.rb 23 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/core_ext/kernel_require.rb 24 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems.rb 25 /Users/rusterholz/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/rubygems/path_support.rb ~~~ **Expected Results:** Given that `String.new.method(:length).super_method` correctly returns nil, I would expect `String.instance_method(:length).bind(String.new).super_method` to also return nil.