network: accept NUL character in SendOption= - #14675

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==51703==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 31 byte(s) in 1 object(s) allocated from:
    #0 0x7f0cf22adaca in __interceptor_malloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x7f0cf159a2ae in malloc_multiply ../src/basic/alloc-util.h:96
    #2 0x7f0cf159a2ae in cunescape_length_with_prefix ../src/basic/escape.c:303
    #3 0x5562d06ca164 in cunescape_length ../src/basic/escape.h:47
    #4 0x5562d06ca164 in cunescape ../src/basic/escape.h:50
    #5 0x5562d06ca81a in test_cunescape ../src/test/test-escape.c:106
    #6 0x5562d06cb954 in main ../src/test/test-escape.c:176
    #7 0x7f0cf0138152 in __libc_start_main (/lib64/libc.so.6+0x27152)

Direct leak of 19 byte(s) in 1 object(s) allocated from:
    #0 0x7f0cf22adaca in __interceptor_malloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x7f0cf159a2ae in malloc_multiply ../src/basic/alloc-util.h:96
    #2 0x7f0cf159a2ae in cunescape_length_with_prefix ../src/basic/escape.c:303
    #3 0x5562d06ca164 in cunescape_length ../src/basic/escape.h:47
    #4 0x5562d06ca164 in cunescape ../src/basic/escape.h:50
    #5 0x5562d06ca7bb in test_cunescape ../src/test/test-escape.c:103
    #6 0x5562d06cb954 in main ../src/test/test-escape.c:176
    #7 0x7f0cf0138152 in __libc_start_main (/lib64/libc.so.6+0x27152)

Direct leak of 13 byte(s) in 1 object(s) allocated from:
    #0 0x7f0cf22adaca in __interceptor_malloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x7f0cf159a2ae in malloc_multiply ../src/basic/alloc-util.h:96
    #2 0x7f0cf159a2ae in cunescape_length_with_prefix ../src/basic/escape.c:303
    #3 0x5562d06ca164 in cunescape_length ../src/basic/escape.h:47
    #4 0x5562d06ca164 in cunescape ../src/basic/escape.h:50
    #5 0x5562d06ca75c in test_cunescape ../src/test/test-escape.c:100
    #6 0x5562d06cb954 in main ../src/test/test-escape.c:176
    #7 0x7f0cf0138152 in __libc_start_main (/lib64/libc.so.6+0x27152)

Direct leak of 10 byte(s) in 1 object(s) allocated from:
    #0 0x7f0cf22adaca in __interceptor_malloc /build/gcc/src/gcc/libsanitizer/asan/asan_malloc_linux.cc:144
    #1 0x7f0cf159a2ae in malloc_multiply ../src/basic/alloc-util.h:96
    #2 0x7f0cf159a2ae in cunescape_length_with_prefix ../src/basic/escape.c:303
    #3 0x5562d06ca164 in cunescape_length ../src/basic/escape.h:47
    #4 0x5562d06ca164 in cunescape ../src/basic/escape.h:50
    #5 0x5562d06ca70f in test_cunescape ../src/test/test-escape.c:97
    #6 0x5562d06cb954 in main ../src/test/test-escape.c:176
    #7 0x7f0cf0138152 in __libc_start_main (/lib64/libc.so.6+0x27152)

SUMMARY: AddressSanitizer: 73 byte(s) leaked in 4 allocation(s).