fix fbsetbg in combination with picky shells

in *BSD, /bin/sh is Almquist Shell(ash). the 'hash' built-in command of ash
returns 0, always. 'hash' is not usable for find_it() function in
util/fbsetbg and util/fluxbox-generate_menu.in.

this patch changes the behavior of find_it(): when 'hash' is detected to
not work correctly, switch back to 'which'.


this patch is the work of Yamashiro, Jun and appeared first as patch-160
on sourceforge: https://sourceforge.net/p/fluxbox/patches/160/. i submit
it on behalf of the author.

util/fbsetbg

@@ -133,9 +133,20 @@ Common tips to use with $command:
 EOF
 }
 
+# some shell's hash returns 0 always
+if hash this_program_does_not_exist-no_really-aA1zZ9 > /dev/null 2>&1; then
+    # can't rely on return value
+    # ash / ksh
     find_it() {
-    [ -n "$1" ] && hash $1 2> /dev/null
+        which "$1" > /dev/null 2>&1
     }
+else
+    # can rely on return value
+    # bash / dash / zsh / sh on Solaris
+    find_it() {
+        [ -n "$1" ] && hash "$1" 2> /dev/null
+    }
+fi
 
 message() {
 

util/fluxbox-generate_menu.in

@@ -145,13 +145,28 @@ testoption() {
     esac
 }
 
+# some shell's hash returns 0 always
+if hash this_program_does_not_exist-no_really-aA1zZ9 > /dev/null 2>&1; then
+    # can't rely on return value
+    # ash / ksh
     find_it() {
-    [ -n "$1" ] && hash $1 2> /dev/null && shift && "$@"
+        which "$1" > /dev/null 2>&1 && shift && "$@"
     }
 
     find_it_options() {
-    [ -n "$1" ] && hash $1 2> /dev/null
+        which "$1" > /dev/null 2>&1
     }
+else
+    # can rely on return value
+    # bash / dash / zsh / sh on Solaris
+    find_it() {
+        [ -n "$1" ] && hash "$1" 2> /dev/null && shift && "$@"
+    }
+
+    find_it_options() {
+        [ -n "$1" ] && hash "$1" 2> /dev/null
+    }
+fi
 
 #echo "replaceWithinString: $1, $2, $3" >&2
 #echo ${1//$2/$3} # causes error in BSD even though not used
@@ -203,7 +218,7 @@ convertIcon(){
     if [ -f "${entry_icon}" ]; then
         : echo "File exists. To overwrite, type: convert \"$1\" \"$entry_icon\"" >&2
     else
-        if hash convert 2> /dev/null; then
+        if find_it_options convert; then
             convert "$1" "$entry_icon"
             # echo convert "$1" , "$entry_icon" >> $ICONMAPPING
         else