47 lines
1.5 KiB
Diff
47 lines
1.5 KiB
Diff
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344411: $RANDOM stays the same when job executed in the background
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In bash 3.0, random was seeded whenever subshell_environment != 0.
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In bash 3.2, random was seeded whenever subshell_environment != 0 &&
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seeded_subshell == 0. And when it was seeded, seeded_subshell was set to 1.
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Therefore, in 3.2, if you seeded random in a subshell and in this subshell
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invoked another one, it wasn't reseeded as it should have been. A testcase for
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that is this:
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( echo $RANDOM; ( echo $RANDOM ); ( echo $RANDOM ) )
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Tomas's patch (bash-3.2-rng.patch) changed the code to use subshell_level.
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subshell_level is not increased for simple async commands, however. So,
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although he fixed the previous case, he introduced another. Here's a testcase:
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echo $RANDOM; echo $RANDOM & echo $RANDOM &
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I decided to just compare the pids, that should be safe enough.
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Written-by: Tomas Janousek <tjanouse@redhat.com>
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Reviewed-by: Tomas Mraz <tmraz@redhat.com>
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--- bash-3.2/variables.c.344411 2007-11-06 19:26:42.000000000 +0100
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+++ bash-3.2/variables.c 2007-11-06 20:27:25.000000000 +0100
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@@ -1211,7 +1211,7 @@
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arrayind_t unused;
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{
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sbrand ((unsigned int)strtoul (value, (char **)NULL, 10));
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- seeded_subshell = subshell_level;
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+ seeded_subshell = getpid();
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return (self);
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}
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@@ -1221,10 +1221,10 @@
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int rv;
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/* Reset for command and process substitution. */
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- if (seeded_subshell < subshell_level)
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+ if (seeded_subshell != getpid())
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{
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seed_random ();
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- seeded_subshell = subshell_level;
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+ seeded_subshell = getpid();
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}
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do
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