Re: [PATCH] Fix hexdump command used for mercurial dirstate parsing

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Bart Schaefer wrote on Sun, Oct 30, 2016 at 11:28:32 -0700:
> On Oct 30,  5:06pm, Daniel Shahaf wrote:
> }
> }     setopt localoptions extendedglob
> }     local -r -A pad=( $'\0' 0 $'\1' 0 $'\2' 0 $'\3' 0 $'\4' 0 $'\5' 0 $'\6' 0 $'\7' 0 $'\10' 0 $'\11' 0 $'\12' 0 $'\13' 0 $'\14' 0 $'\15' 0 $'\16' 0 $'\17' 0 )
> }     REPLY=${(L)val//(#b)(?)/$pad[$match[1]]$(( [##16] ##${match[1]} ))}
> 
> I can't help thinking here must be an easier way to do that.
> 
> f() {                                              
>   setopt localoptions nomultibyte extendedglob
>   local val
>   read -k $2 -u 0 val <$1
>   print -r -- ${(Lj::)${(l:2::0:)${(@s//)val}//(#m)*/$(( [##16] ##$MATCH ))}}
> }

Thanks; that's now VCS_INFO_hexdump:

diff --git a/Functions/VCS_Info/VCS_INFO_hexdump b/Functions/VCS_Info/VCS_INFO_hexdump
index e69de29..11f1c1a 100644
--- a/Functions/VCS_Info/VCS_INFO_hexdump
+++ b/Functions/VCS_Info/VCS_INFO_hexdump
@@ -0,0 +1,16 @@
+## vim:ft=zsh
+
+# VCS_INFO_hexdump FILENAME BYTECOUNT
+#
+# Return in $REPLY a hexadecimal representation (lowercase, no whitespace)
+# of the first BYTECOUNT bytes of FILENAME.
+
+if [[ -r $1 ]]; then
+  setopt localoptions nomultibyte extendedglob
+  local val
+  read -k $2 -u 0 val <$1
+  REPLY=${(Lj::)${(l:2::0:)${(@s//)val}//(#m)*/$(( [##16] ##$MATCH ))}}
+else
+  return 1
+fi
+
diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg b/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
index f35ad59..4ad4089 100644
--- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
+++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_hg
@@ -40,9 +40,9 @@ VCS_INFO_adjust
 # Disabled by default anyway, so no harm done.
 if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" get-revision ; then
     if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" use-simple \
-            && ( VCS_INFO_check_com hexdump ) && [[ -r ${dirstatefile} ]] ; then
+            && VCS_INFO_hexdump ${dirstatefile} 20 ; then
         # Calling hexdump is (much) faster than hg but doesn't get the local rev
-        r_csetid=$(hexdump -n 20 -e '1/1 "%02x"' ${dirstatefile})
+        r_csetid=$REPLY
     else
         # Settling for a short (but unique!) hash because getting the full
         # 40-char hash in addition to all the other info we want isn't
diff --git a/Functions/VCS_Info/vcs_info b/Functions/VCS_Info/vcs_info
index f13f6b5..c0c1182 100644
--- a/Functions/VCS_Info/vcs_info
+++ b/Functions/VCS_Info/vcs_info
@@ -19,6 +19,7 @@ static_functions=(
     VCS_INFO_check_com
     VCS_INFO_formats
     VCS_INFO_get_cmd
+    VCS_INFO_hexdump
     VCS_INFO_hook
     VCS_INFO_maxexports
     VCS_INFO_nvcsformats