A bug is found that might be located in cygwin or bash. Bash dumps stack on exit if all of the following requirements are true: - Bash was started from a windows batch script - Bash was started in non-interactive mode to execute a script - The script includes an attempt to write (pipe) data to a file in /etc - The write attempt is enclosed by an if clause.
To reproduce the bug, start a windows batch script that starts bash in non-interactive mode running a bash script that within an if clause attempts to write to a file in the /etc directory. This will result in a bash stack dump, at least on Windows 7 Professional SP1. As an example, place example*.bat and script*.bash (code listed below) in the cygwin root folder. Then start the batch files via the Windows GUI. example1-breaks.bat reproduces the bug. example1i-works.bat shows that bash works like expected in interactive mode. example2-works.bat shows that bash works like expected when writing to a file outside of /etc. example3-maybe.bat shows that the if clause might change the behaviour. File listing follows. Make sure to save the .bat files with windows linebreaks, and the .bash files with unix linebreaks. example1-breaks.bat: @echo off %~d0 cd %~dp0 bin\bash.exe script1.bash pause example1i-works.bat: @echo off %~d0 cd %~dp0 bin\bash.exe -i script1.bash pause example2-works.bat: @echo off %~d0 cd %~dp0 bin\bash.exe script2.bash pause example3-maybe.bat: @echo off %~d0 cd %~dp0 bin\bash.exe script3.bash pause script1.bash: #!/bin/bash PATH="/bin:$PATH" if true; then echo hello > /etc/hello fi script2.bash: #!/bin/bash PATH="/bin:$PATH" if true; then echo hello > /hello fi script3.bash: #!/bin/bash PATH="/bin:$PATH" echo hello > /etc/hello fi System information: Machine: i686 OS: cygwin on Windows 7 Professional SP1 Compiler: gcc-4 Compilation CFLAGS: -DPROGRAM='bash.exe' -DCONF_HOSTTYPE='i686' -DCONF_OSTYPE='cygwin' -DCONF_MACHTYPE='i686-pc-cygwin' -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/$ uname output: CYGWIN_NT-6.1 Machine-name 1.7.16(0.262/5/3) 2012-07-20 22:55 i686 Cygwin Machine Type: i686-pc-cygwin See also attached cygcheck.out. It was created by cygcheck running independently from any cygwin installation. "WITHHELD" denotes a manual alteration.
cygcheck.out
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