Merge pull request #994 from akinomyoga/_comp_compgen

fix: use `_comp_compgen` for the remaining cases

Author: scop

CONTRIBUTING.md

@@ -117,15 +117,21 @@ Also, please bear the following coding guidelines in mind:
   variables are set (e.g. with `[[ -v varname ]]`) or use default
   expansion (e.g. `${varname-}`).
 
-- Prefer `compgen -W '...' -- $cur` over embedding `$cur` in external
-  command arguments (often e.g. sed, grep etc) unless there's a good
-  reason to embed it. Embedding user input in command lines can result
-  in syntax errors and other undesired behavior, or messy quoting
-  requirements when the input contains unusual characters. Good
-  reasons for embedding include functionality (if the thing does not
-  sanely work otherwise) or performance (if it makes a big difference
-  in speed), but all embedding cases should be documented with
-  rationale in comments in the code.
+- Prefer `_comp_compgen_split -- "$(...)"` over embedding `$cur` in external
+  command arguments (often e.g. sed, grep etc) unless there's a good reason to
+  embed it. Embedding user input in command lines can result in syntax errors
+  and other undesired behavior, or messy quoting requirements when the input
+  contains unusual characters.  Good reasons for embedding include
+  functionality (if the thing does not sanely work otherwise) or performance
+  (if it makes a big difference in speed), but all embedding cases should be
+  documented with rationale in comments in the code.
+
+  Do not use `_comp_compgen -- -W "$(...)"` or `_comp_compgen -- -W '$(...)'`
+  but always use `_comp_compgen_split -- "$(...)"`.  In the former case, when
+  the command output contains strings looking like shell expansions, the
+  expansions will be unexpectedly performed, which becomes a vulnerability.  In
+  the latter case, checks by shellcheck and shfmt will not be performed inside
+  `'...'`.  Also, `_comp_compgen_split` is `IFS`-safe.
 
 - When completing available options, offer only the most descriptive
   ones as completion results if there are multiple options that do the

bash_completion

@@ -665,12 +665,14 @@ _comp_compgen()
 # caller _comp_compgen, the words are appended to the existing elements of the
 # array instead of replacing the existing elements.  This function ignores
 # ${cur-} or the prefix specified by `-v CUR`.
+# @return 0 if at least one completion is generated, or 1 otherwise.
 # @since 2.12
 _comp_compgen_set()
 {
     local _append=${_comp_compgen__append-}
     local _var=${_comp_compgen__var-COMPREPLY}
     eval -- "$_var${_append:++}=(\"\$@\")"
+    (($#))
 }
 
 # Simply split the text and generate completions.  This function should be used
@@ -1004,6 +1006,7 @@ _comp_quote_compgen()
 # @param $1  If `-d', complete only on directories.  Otherwise filter/pick only
 #            completions with `.$1' and the uppercase version of it as file
 #            extension.
+# @return 0 if at least one completion is generated, or 1 otherwise.
 #
 # @since 2.12
 _comp_compgen_filedir()
@@ -1021,6 +1024,9 @@ _comp_compgen_filedir()
         local _quoted=$ret
         _comp_unlocal ret
 
+        # work around bash-4.2 where compgen -f "''" produces nothing.
+        [[ $_quoted == "''" ]] && _quoted=""
+
         # Munge xspec to contain uppercase version too
         # https://lists.gnu.org/archive/html/bug-bash/2010-09/msg00036.html
         # news://news.gmane.io/4C940E1C.1010304@case.edu
@@ -2575,7 +2581,6 @@ _comp_command_offset()
     _comp_get_words cur
 
     if ((COMP_CWORD == 0)); then
-        local IFS=$'\n'
         compopt -o filenames
         _comp_compgen -- -d -c
     else

completions/bzip2

@@ -26,7 +26,7 @@ _comp_cmd_bzip2()
         return
     fi
 
-    local IFS=$'\n' xspec="*.?(t)bz2"
+    local xspec="*.?(t)bz2"
 
     if [[ $prev == --* ]]; then
         [[ $prev == --@(decompress|list|test) ]] && xspec="!"$xspec

completions/cd

@@ -13,7 +13,7 @@ _comp_cmd_cd()
         return
     fi
 
-    local IFS=$'\n' i j k
+    local i j k
 
     compopt -o filenames
 
@@ -25,8 +25,8 @@ _comp_cmd_cd()
     fi
 
     local mark_dirs="" mark_symdirs=""
-    _comp_readline_variable_on mark-directories && mark_dirs=y
-    _comp_readline_variable_on mark-symlinked-directories && mark_symdirs=y
+    _comp_readline_variable_on mark-directories && mark_dirs=set
+    _comp_readline_variable_on mark-symlinked-directories && mark_symdirs=set
 
     # we have a CDPATH, so loop on its contents
     local paths dirs

completions/config_list

@@ -15,8 +15,8 @@ _comp_cmd_config_list()
     [[ $was_split ]] && return
 
     if [[ $cur == -* ]]; then
-        COMPREPLY=($(compgen -W '--inputfile --outputfile --checkonly
-            --verbose --help' -- "$cur"))
+        _comp_compgen -- -W '--inputfile --outputfile --checkonly
+            --verbose --help'
     else
         # Prefer `list_lists` in the same dir as command
         local pathcmd

completions/cpio

@@ -31,8 +31,8 @@ _comp_cmd_cpio()
     [[ $was_split ]] && return
 
     if ((cword == 1)); then
-        COMPREPLY=($(compgen -W '-o --create -i --extract -p --pass-through
-            -? --help --license --usage --version' -- "$cur"))
+        _comp_compgen -- -W '-o --create -i --extract -p --pass-through -?
+            --help --license --usage --version'
     else
         case ${words[1]} in
             -o | --create)

completions/gzip

@@ -27,7 +27,7 @@ _comp_cmd_gzip()
         return
     fi
 
-    local IFS=$'\n' xspec="*.@(gz|t[ag]z)"
+    local xspec="*.@(gz|t[ag]z)"
     [[ ${1##*/} == pigz ]] && xspec="*.@([gz]z|t[ag]z)"
 
     if [[ $prev == --* ]]; then

completions/ipmitool

@@ -19,7 +19,7 @@ _comp_cmd_ipmitool()
             local -a files
             _comp_expand_glob files '/dev/ipmi* /dev/ipmi/* /dev/ipmidev/*'
             ((${#files[@]})) &&
-                COMPREPLY=($(compgen -W '"${files[@]##*([^0-9])}"' -X '![0-9]*' -- "$cur"))
+                _comp_compgen -- -W '"${files[@]##*([^0-9])}"' -X '![0-9]*'
             return
             ;;
         -*I)

completions/java

@@ -81,11 +81,11 @@ _comp_cmd_java__classes()
             fi
 
         elif [[ -d $i ]]; then
-            COMPREPLY+=(
-                $(compgen -d -- "$i/$cur" | command sed -e "s|^$i/\(.*\)|\1.|")
-                $(compgen -f -X '!*.class' -- "$i/$cur" |
-                    command sed -e '/\$/d' -e "s|^$i/||")
-            )
+            local tmp
+            _comp_compgen -v tmp -c "$i/$cur" -- -d -S .
+            _comp_compgen -av tmp -c "$i/$cur" -- -f -X '!*.class'
+            ((${#tmp[@]})) &&
+                _comp_compgen -a -- -X '*\$*' -W '"${tmp[@]#$i/}"'
             [[ ${COMPREPLY-} == *.class ]] || compopt -o nospace
 
             # FIXME: if we have foo.class and foo/, the completion

completions/kldload

@@ -18,11 +18,11 @@ _comp_cmd_kldload()
 
     compopt -o filenames
     for i in "${moddirs[@]}"; do
-        modules=($(compgen -f "$i/$cur"))
-        modules=(${modules[@]#$i/})
-        COMPREPLY+=("${modules[@]}")
+        _comp_compgen -v modules -c "$i/$cur" -- -f &&
+            COMPREPLY+=("${modules[@]#$i/}")
     done
-    COMPREPLY=(${COMPREPLY[@]%.ko})
+    ((${#COMPREPLY[@]})) &&
+        COMPREPLY=("${COMPREPLY[@]%.ko}")
 
     # also add dirs in current dir
     _comp_compgen -a filedir -d