out of bounds heap read in cmd_search

[hannob]

Script input:
https://crashes.fuzzing-project.org/radare2-script-oob-heap-read-cmd_search-2
Contains string "/v". There already was #2850 which was similar.

Address Sanitizer:

==453==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000156d3 at pc 0x7fadf020fbaa bp 0x7ffc9df89c50 sp 0x7ffc9df89c40
READ of size 1 at 0x6020000156d3 thread T0
    #0 0x7fadf020fba9 in cmd_search /f/radare2/radare2/libr/core/cmd_search.c:1791
    #1 0x7fadf023bb1a in r_core_cmd_subst_i /f/radare2/radare2/libr/core/cmd.c:1599
    #2 0x7fadf019ca51 in r_core_cmd_subst /f/radare2/radare2/libr/core/cmd.c:1084
    #3 0x7fadf019de72 in r_core_cmd /f/radare2/radare2/libr/core/cmd.c:1947
    #4 0x7fadf01a0d1c in r_core_cmd_lines /f/radare2/radare2/libr/core/cmd.c:1998
    #5 0x7fadf01a107c in r_core_cmd_file /f/radare2/radare2/libr/core/cmd.c:2010
    #6 0x7fadf01a4013 in r_core_run_script /f/radare2/radare2/libr/core/cmd.c:373
    #7 0x405642 in main /f/radare2/radare2/binr/radare2/radare2.c:733
    #8 0x7fadea6f2f9f in __libc_start_main (/lib64/libc.so.6+0x1ff9f)
    #9 0x40a3fd (/mnt/ram/r2/radare2+0x40a3fd)

0x6020000156d3 is located 0 bytes to the right of 3-byte region [0x6020000156d0,0x6020000156d3)
allocated by thread T0 here:
    #0 0x7fadf08ed6f7 in malloc (/usr/lib/gcc/x86_64-pc-linux-gnu/4.9.2/libasan.so.1+0x576f7)
    #1 0x7fadea754789 in strdup (/lib64/libc.so.6+0x81789)

SUMMARY: AddressSanitizer: heap-buffer-overflow /f/radare2/radare2/libr/core/cmd_search.c:1791 cmd_search
Shadow bytes around the buggy address:
  0x0c047fffaa80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaa90: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaaa0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaab0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
  0x0c047fffaac0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
=>0x0c047fffaad0: fa fa 00 01 fa fa 01 fa fa fa[03]fa fa fa 03 fa
  0x0c047fffaae0: fa fa 03 fa fa fa fd fd fa fa fd fd fa fa 06 fa
  0x0c047fffaaf0: fa fa fd fa fa fa fd fa fa fa fd fa fa fa fd fa
  0x0c047fffab00: fa fa fd fa fa fa fd fa fa fa fd fd fa fa 02 fa
  0x0c047fffab10: fa fa fd fa fa fa fd fd fa fa fd fa fa fa fd fd
  0x0c047fffab20: fa fa fd fa fa fa fd fa fa fa fd fd fa fa fd fd
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Heap right redzone:      fb
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack partial redzone:   f4
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Contiguous container OOB:fc
  ASan internal:           fe
==453==ABORTING