Fix apropos completions

The 'str' variable was apparently mistakenly removed by 49c5f96470.

Re-add it, and regex-escape it as well.

Allow completing on apropos <TAB> instaed of requiring an initial char.

Use __fish_apropos instead of apropos.

New regex to hopefully work on more platforms.

Explicitly use ^ instead of adding it at __fish_apropos

share/completions/apropos.fish

@@ -1,11 +1,10 @@
 function __fish_complete_apropos
-    if test (commandline -ct)
-        switch (commandline -ct)
+    set -f str (commandline -ct | string escape --style=regex)
+    switch "$str"
         case '-**'
 
         case '*'
-                apropos $str 2>/dev/null | string replace -rf -- "^(.*$str([^ ]*).*)" "$str\$2\t\$1"
-        end
+            __fish_apropos "^$str" 2>/dev/null | string replace -rf -- '^([^(\s]+) ?\([,\w]+\)\s+-?\s?(.*)$' '$1\t$2'
     end
 end
 

share/functions/__fish_apropos.fish

@@ -36,7 +36,7 @@ if test $status -eq 0 -a (count $sysver) -eq 3
             set age (path mtime -R -- $whatis)
         end
 
-        MANPATH="$dir" apropos "^$argv"
+        MANPATH="$dir" apropos "$argv"
 
         if test $age -ge $max_age
             test -d "$dir" || mkdir -m 700 -p $dir
@@ -46,6 +46,8 @@ if test $status -eq 0 -a (count $sysver) -eq 3
     end
 else
     function __fish_apropos
-        apropos $argv
+        # we only ever prefix match for completions. This also ensures results for bare apropos <TAB>
+        # (apropos '' gives no results, but apropos '^' lists all manpages)
+        apropos "$argv"
     end
 end

share/functions/__fish_complete_man.fish

@@ -32,7 +32,7 @@ function __fish_complete_man
 
     if test -n "$token"
         # Do the actual search
-        __fish_apropos $token 2>/dev/null | awk '
+        __fish_apropos ^$token 2>/dev/null | awk '
                 BEGIN { FS="[\t ]- "; OFS="\t"; }
                 # BSD/Darwin
                 /^[^( \t]+(, [^( \t]+)*\('$section'\)/ {

share/functions/__fish_describe_command.fish

@@ -12,7 +12,7 @@ end
 function __fish_describe_command -d "Command used to find descriptions for commands"
     # $argv will be inserted directly into the awk regex, so it must be escaped
     set -l argv_regex (string escape --style=regex -- "$argv")
-    __fish_apropos $argv 2>/dev/null | awk -v FS=" +- +" '{
+    __fish_apropos ^$argv 2>/dev/null | awk -v FS=" +- +" '{
 		split($1, names, ", ");
 		for (name in names)
 			if (names[name] ~ /^'"$argv_regex"'.* *\([18]\)/ ) {