Re: argv subscript range uses too many memory

[Han Pingtian <hanpt@xxxxxxxxxxxxxxxxxx>]

Looks like when running with 'print -- "$argv[1,3]", the call trace is
something like this:

(gdb) bt
#0  mmap_heap_alloc (n=0x7fff0852e880) at mem.c:449
#1  0x000000000045f5f9 in zhalloc (size=1594456) at mem.c:542
#2  0x00000000004a4dfa in arrdup (s=0x313b008) at utils.c:3648
#3  0x0000000000471fa9 in getarrvalue (v=0x7fff0852ea20) at params.c:2174
#4  0x00000000004961bf in paramsubst (l=0x7f51d6dd0bb0, n=0x7f51d6dd0bf8, str=0x7fff0852ee38, qt=1, pf_flags=0) at subst.c:2400
#5  0x0000000000491cbd in stringsubst (list=0x7f51d6dd0bb0, node=0x7f51d6dd0bf8, pf_flags=0, asssub=1) at subst.c:236
#6  0x0000000000491089 in prefork (list=0x7f51d6dd0bb0, flags=1) at subst.c:77
#7  0x000000000042dafb in execcmd (state=0x7fff0852f760, input=0, output=0, how=18, last1=2) at exec.c:2579
#8  0x000000000042b410 in execpline2 (state=0x7fff0852f760, pcode=323, how=18, input=0, output=0, last1=0) at exec.c:1677
#9  0x000000000042a56e in execpline (state=0x7fff0852f760, slcode=5122, how=18, last1=0) at exec.c:1462
#10 0x0000000000429c2c in execlist (state=0x7fff0852f760, dont_change_job=0, exiting=0) at exec.c:1245
#11 0x000000000042968a in execode (p=0x7f51d6dd0af0, dont_change_job=0, exiting=0, context=0x4af417 "toplevel") at exec.c:1057
#12 0x0000000000447dcb in loop (toplevel=1, justonce=0) at init.c:185
#13 0x000000000044b3f4 in zsh_main (argc=1, argv=0x7fff0852f938) at init.c:1616
#14 0x000000000040e034 in main (argc=1, argv=0x7fff0852f938) at ./main.c:93
(gdb)

But if running with 'print -- "$argv[1] $argv[2] $argv[3]", the call
trace is something like this:

(gdb) bt
#0  mmap_heap_alloc (n=0x7fff0852f4a0) at mem.c:449
#1  0x000000000045f5f9 in zhalloc (size=16) at mem.c:542
#2  0x0000000000490a1d in dupstring (s=0x4baa95 "%B%S%#%s%b") at string.c:39
#3  0x0000000000488f5c in promptexpand (s=0x4baa95 "%B%S%#%s%b", ns=1, rs=0x0, Rs=0x0, txtchangep=0x0) at prompt.c:185
#4  0x000000000049f6d6 in preprompt () at utils.c:1307
#5  0x0000000000447b11 in loop (toplevel=1, justonce=0) at init.c:121
#6  0x000000000044b3f4 in zsh_main (argc=1, argv=0x7fff0852f938) at init.c:1616
#7  0x000000000040e034 in main (argc=1, argv=0x7fff0852f938) at ./main.c:93

And the outputs showed before hitting the break point mmap_heap_alloc().