doc: Mention glibc initstate, initstate_r bug

[Bruno Haible]

There's a test failure on cfarm105.cfarm.net:

../../build-aux/test-driver: line 112: 3107617 Bus error               "$@" >> 
"$log_file" 2>&1
FAIL: test-random_r

Just documenting it should be enough, since most state arrays allocated by
applications should be aligned by the compiler or through malloc().


2023-06-25  Bruno Haible  <bruno@clisp.org>

        doc: Mention glibc initstate, initstate_r bug.
        * doc/posix-functions/initstate.texi: Mention glibc bug.
        * doc/glibc-functions/initstate_r.texi: Likewise.
        * tests/test-random_r.c: Add a comment.

diff --git a/doc/glibc-functions/initstate_r.texi 
b/doc/glibc-functions/initstate_r.texi
index b2bcc18cf8..9c1ea829db 100644
--- a/doc/glibc-functions/initstate_r.texi
+++ b/doc/glibc-functions/initstate_r.texi
@@ -32,6 +32,10 @@
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+This function crashes if the state buffer is unaligned on on some platforms:
+@c https://sourceware.org/bugzilla/show_bug.cgi?id=30584
+glibc 2.36/sparc.
+@item
 This function has a slightly different (but compatible) declaration on some
 platforms:
 Haiku 2017.
diff --git a/doc/posix-functions/initstate.texi 
b/doc/posix-functions/initstate.texi
index 2f7a83ca95..a1de753e1f 100644
--- a/doc/posix-functions/initstate.texi
+++ b/doc/posix-functions/initstate.texi
@@ -19,6 +19,10 @@
 Portability problems not fixed by Gnulib:
 @itemize
 @item
+This function crashes if the state buffer is unaligned on on some platforms:
+@c https://sourceware.org/bugzilla/show_bug.cgi?id=30584
+glibc 2.36/sparc.
+@item
 The first parameter is @code{unsigned long} instead of @code{unsigned int} on
 some platforms:
 MidnightBSD 2.0.
diff --git a/tests/test-random_r.c b/tests/test-random_r.c
index dffa709f5e..0dacd360ae 100644
--- a/tests/test-random_r.c
+++ b/tests/test-random_r.c
@@ -29,6 +29,9 @@ SIGNATURE_CHECK (random_r, int, (struct random_data *, 
int32_t *));
 
 #include "macros.h"
 
+/* Note: This test crashes on glibc/SPARC systems.
+   Reported at <https://sourceware.org/bugzilla/show_bug.cgi?id=30584>.  */
+
 static int
 test_failed (int alignment)
 {