#15250: jam crashes when given empty input file
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Reporter: simonsouth | Owner: bonefish
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: Build System | Version: R1/Development
Keywords: | Blocked By:
Blocking: | Has a Patch: 0
Platform: All |
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jam will crash with a segmentation fault if given an empty input file to
parse. This can happen if a user deletes every line from his
UserBuildConfig, for instance, without deleting the file itself.
To demonstrate on Haiku, from within a "generated" subfolder beneath the
Haiku source tree:
{{{
mv ../build/jam/UserBuildConfig{,.orig}
touch ../build/jam/UserBuildConfig
jam -q # This will segfault
mv ../build/jam/UserBuildConfig{.orig,}
}}}
This happens because as part of its file-caching mechanism, jam will
allocate ''but not initialize'' an array of string pointers to hold lines
read from the file. If no lines are read (because the file is empty) the
first element of the array is never replaced with a valid pointer, causing
a segfault later when the program tries to parse the file's contents.
Changing jam so it initializes the first element of the array to zero
solves the problem.
I'll upload a patch for review.
--
Ticket URL: <https://dev.haiku-os.org/ticket/15250>
Haiku <https://dev.haiku-os.org>
The Haiku operating system.
