Merge pull request #1074 from akinomyoga/patsub_replacement

fix: work around `shopt -s patsub_replacement` newly supported in Bash 5.2

Author: akinomyoga

bash_completion

@@ -1572,8 +1572,8 @@ _comp_compgen_usage()
 _comp_compgen_signals()
 {
     local -a sigs
-    _comp_compgen -v sigs -c "SIG${cur#"${1-}"}" -- -P "${1-}" -A signal &&
-        _comp_compgen -U sigs set "${sigs[@]/#${1-}SIG/${1-}}"
+    _comp_compgen -v sigs -c "SIG${cur#"${1-}"}" -- -A signal &&
+        _comp_compgen -RU sigs -- -P "${1-}" -W '"${sigs[@]#SIG}"'
 }
 
 # This function completes on known mac addresses
@@ -2047,9 +2047,8 @@ _comp_compgen_usergroups()
         if ((${#tmp[@]})); then
             local _prefix=${cur%%*([^:])}
             _prefix=${_prefix//\\/}
-            local -a _tmp=("${tmp[@]/#/$_prefix}")
-            _comp_unlocal tmp
-            _comp_compgen_set "${_tmp[@]}"
+            _comp_compgen -Rv tmp -- -P "$_prefix" -W '"${tmp[@]}"'
+            _comp_compgen -U tmp set "${tmp[@]}"
         fi
     elif [[ $cur == *:* ]]; then
         # Completing group after 'user:gr<TAB>'.
@@ -2455,7 +2454,9 @@ _comp__included_ssh_config_files()
 #     -p PREFIX      Use PREFIX
 #     -4             Filter IPv6 addresses from results
 #     -6             Filter IPv4 addresses from results
-# @return Completions, starting with CWORD, are added to COMPREPLY[]
+# @var[out] COMPREPLY  Completions, starting with CWORD, are added
+# @return True (0) if one or more completions are generated, or otherwise False
+# (1).
 # @since 2.12
 _comp_compgen_known_hosts()
 {

completions/_mount.linux

@@ -25,7 +25,7 @@ _comp_cmd_mount()
                 ufs umsdos usbfs vfat xfs'
             _comp_compgen -a fstypes
             [[ $split ]] && ((${#COMPREPLY[@]})) &&
-                COMPREPLY=(${COMPREPLY[@]/#/$prev,})
+                _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"${COMPREPLY[@]}"'
             return
             ;;
         --bind | -B | --rbind | -R)
@@ -204,7 +204,7 @@ _comp_cmd_mount()
             # COMP_WORDBREAKS is a real pain in the ass
             prev="${prev##*["$COMP_WORDBREAKS"]}"
             [[ $split ]] && ((${COMPREPLY[@]})) &&
-                COMPREPLY=(${COMPREPLY[@]/#/"$prev,"})
+                _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"${COMPREPLY[@]}"'
             [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
             return
             ;;

completions/_umount.linux

@@ -111,7 +111,7 @@ _comp_cmd_umount()
                 usbfs vfat xfs'
             _comp_compgen -a fstypes
             [[ $split ]] && ((${#COMPREPLY[@]})) &&
-                COMPREPLY=(${COMPREPLY[@]/#/$prev,})
+                _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"${COMPREPLY[@]}"'
             return
             ;;
         -O)

completions/chromium-browser

@@ -17,8 +17,8 @@ _comp_cmd_chromium_browser()
             case $cur in
                 *://*)
                     local prefix="${cur%%://*}://"
-                    _comp_compgen_known_hosts -- "${cur#*://}"
-                    COMPREPLY=("${COMPREPLY[@]/#/$prefix}")
+                    _comp_compgen_known_hosts -- "${cur#*://}" &&
+                        _comp_compgen -Rv COMPREPLY -- -P "$prefix" -W '"${COMPREPLY[@]}"'
                     _comp_ltrim_colon_completions "$cur"
                     ;;
                 *)

completions/cppcheck

@@ -24,8 +24,9 @@ _comp_cmd_cppcheck()
                 split="set"
             fi
             _comp_compgen -- -W 'all warning style performance portability
-                information unusedFunction missingInclude'
-            [[ $split ]] && COMPREPLY=(${COMPREPLY[@]/#/"$prev,"})
+                information unusedFunction missingInclude' &&
+                [[ $split ]] &&
+                _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"${COMPREPLY[@]}"'
             return
             ;;
         --error-exitcode)

completions/cvs

@@ -5,8 +5,8 @@ _comp_cmd_cvs__entries()
     local prefix=${cur%/*}/ IFS=$'\n'
     [[ -e ${prefix-}CVS/Entries ]] || prefix=""
     entries=($(cut -d/ -f2 -s "${prefix-}CVS/Entries" 2>/dev/null))
-    if [[ $entries ]]; then
-        entries=("${entries[@]/#/${prefix-}}")
+    if ((${#entries[@]})); then
+        _comp_compgen -Rv entries -- -P "${prefix-}" -W '"${entries[@]}"'
         compopt -o filenames
     fi
 }

completions/info

@@ -51,7 +51,7 @@ _comp_cmd_info()
 
     _comp_split -F : infopath "$infopath"
     if ((${#infopath[@]})); then
-        infopath=("${infopath[@]/%//$cur*}")
+        _comp_compgen -Rv infopath -- -S "/$cur*" -W '"${infopath[@]}"'
         local IFS=
         _comp_expand_glob COMPREPLY '${infopath[@]}'
         _comp_unlocal IFS

completions/kcov

@@ -33,10 +33,10 @@ _comp_cmd_kcov()
                 cur="${cur##*,}"
                 _comp_compgen -- -W "{0..100}"
                 ((${#COMPREPLY[@]} == 1)) &&
-                    COMPREPLY=(${COMPREPLY/#/$prev,})
+                    _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"$COMPREPLY"'
             else
                 _comp_compgen -- -W "{0..100}"
-                ((${#COMPREPLY[@]} == 1)) && COMPREPLY=(${COMPREPLY/%/,})
+                ((${#COMPREPLY[@]} == 1)) && COMPREPLY=("${COMPREPLY/%/,}")
                 compopt -o nospace
             fi
             return

completions/man

@@ -76,9 +76,12 @@ _comp_cmd_man()
 
     _comp_split -F : manpath "$manpath"
     if ((${#manpath[@]})); then
-        manpath=("${manpath[@]/%//*man$sect/$cur*}" "${manpath[@]/%//*cat$sect/$cur*}")
+        local manfiles
+        _comp_compgen -Rv manfiles -- -S "/*man$sect/$cur*" -W '"${manpath[@]}"'
+        _comp_compgen -aRv manfiles -- -S "/*cat$sect/$cur*" -W '"${manpath[@]}"'
+
         local IFS=
-        _comp_expand_glob COMPREPLY '${manpath[@]}'
+        _comp_expand_glob COMPREPLY '${manfiles[@]}'
         _comp_unlocal IFS
 
         if ((${#COMPREPLY[@]} != 0)); then

completions/mr

@@ -16,7 +16,7 @@ _comp_cmd_mr()
         done
     )"
     # Split [online|offline] and remove `action` placeholder.
-    commands="${commands//@(action|[\[\|\]])/$'\n'}"
+    commands="${commands//@(action|[\[\|\]])/ }"
     # Add standard aliases.
     commands="${commands} ci co ls"
     _comp_split commands "$commands"

completions/mutt

@@ -136,7 +136,10 @@ _comp_cmd_mutt__filedir()
     elif [[ $cur == !* ]]; then
         spoolfile="$("$muttcmd" -F "$muttrc" -Q spoolfile 2>/dev/null |
             command sed -e 's|^spoolfile=\"\(.*\)\"$|\1|')"
-        [[ $spoolfile ]] && eval cur="${cur/^!/$spoolfile}"
+        if [[ $spoolfile ]]; then
+            _comp_dequote "\"$spoolfile\"" && spoolfile=$REPLY
+            cur=$spoolfile${cur:1}
+        fi
     fi
     _comp_compgen -c "$cur" filedir
 }

completions/povray

@@ -16,7 +16,8 @@ _comp_cmd_povray()
             cur="${povcur#[-+]I}" # to confuse _comp_compgen_filedir
             pfx="${povcur%"$cur"}"
             _comp_compgen_filedir pov
-            ((${#COMPREPLY[@]})) && COMPREPLY=("${COMPREPLY[@]/#/$pfx}")
+            ((${#COMPREPLY[@]})) &&
+                _comp_compgen -Rv COMPREPLY -- -P "$pfx" -W '"${COMPREPLY[@]}"'
             return
             ;;
         [-+]O*)
@@ -35,12 +36,16 @@ _comp_cmd_povray()
                 IFS=$'\n'
                 command grep '^[-+]I' <<<"${words[*]}"
             ))
-            COMPREPLY=(${COMPREPLY[@]#[-+]I})
-            COMPREPLY=(${COMPREPLY[@]/%.pov/.$oext})
+            _comp_compgen -Rv COMPREPLY -- -X '' -W '"${COMPREPLY[@]#[-+]I}"'
+            local i
+            for i in "${!COMPREPLY[@]}"; do
+                COMPREPLY[i]=${COMPREPLY[i]/%.pov/".$oext"}
+            done
             cur="${povcur#[-+]O}" # to confuse _comp_compgen_filedir
             pfx="${povcur%"$cur"}"
             _comp_compgen -a filedir $oext
-            ((${#COMPREPLY[@]})) && COMPREPLY=("${COMPREPLY[@]/#/$pfx}")
+            ((${#COMPREPLY[@]})) &&
+                _comp_compgen -Rv COMPREPLY -- -P "$pfx" -W '"${COMPREPLY[@]}"'
             return
             ;;
         *.ini\[ | *.ini\[*[^]]) # sections in .ini files
@@ -50,7 +55,8 @@ _comp_cmd_povray()
             COMPREPLY=($(command sed -ne \
                 's/^[[:space:]]*\[\('"$cur"'[^]]*\]\).*$/\1/p' -- "$pfx"))
             # to prevent [bar] expand to nothing.  can be done more easily?
-            ((${#COMPREPLY[@]})) && COMPREPLY=("${COMPREPLY[@]/#/${pfx}[}")
+            ((${#COMPREPLY[@]})) &&
+                _comp_compgen -Rv COMPREPLY -- -P "${pfx}[" -W '"${COMPREPLY[@]}"'
             return
             ;;
         *)

completions/pylint

@@ -88,7 +88,8 @@ _comp_cmd_pylint()
             [[ $cur == *,* ]] && prefix="${cur%,*},"
             _comp_compgen -c "${cur##*,}" -- -W "HIGH INFERENCE
                 INFERENCE_FAILURE UNDEFINED"
-            ((${#COMPREPLY[@]} == 1)) && COMPREPLY=(${COMPREPLY/#/$prefix})
+            ((${#COMPREPLY[@]} == 1)) &&
+                _comp_compgen -Rv COMPREPLY -- -P "$prefix" -W '"$COMPREPLY"'
             return
             ;;
         --format | -${noargopts}f)

completions/smartctl

@@ -35,8 +35,8 @@ _comp_cmd_smartctl__drivedb()
         prefix=+
         cur="${cur#+}"
     fi
-    _comp_compgen_filedir h
-    [[ $prefix ]] && COMPREPLY=("${COMPREPLY[@]/#/$prefix}")
+    _comp_compgen_filedir h && [[ $prefix ]] &&
+        _comp_compgen -Rv COMPREPLY -- -P "$prefix" -W '"${COMPREPLY[@]}"'
 }
 
 _comp_cmd_smartctl()

doc/styleguide.md

@@ -181,3 +181,52 @@ avoid backslash escaping or use the one that minimizes the use of backslash
 escaping.  When the value contains control characters such as a tab and a
 newline, we do not directly include them but we use backslash escape sequences
 such as `\t` and `\n` in the escape string `$'...'`.
+
+### `patsub_replacement` for array elements
+
+There is a subtlety in quoting of the array expansions with a pattern
+replacement when `shopt -s patsub_replacement` (Bash >= 5.2) is
+enabled (which is the default of Bash >= 5.2).
+
+For example, the array expansions with a pattern replacement may be
+used to add a prefix to every element in an array:
+
+```bash
+# problem in bash >= 5.2
+arr=("${arr[@]/#/$prefix}")
+```
+
+However, this has the problem.  The characters `&` contained in
+`$prefix`, if any, will be replaced with the matched string.  The
+unexpected `patsub_replacement` may be suppressed by quoting the
+replacement as
+
+```bash
+# problem with bash <= 4.2 or "shopt -s compat42"
+arr=("${arr[@]/#/"$prefix"}")
+```
+
+However, this has another problem in bash < 4.3 or when `shopt -s
+compat42` is turned on.  The inner double quotations are treated
+literally so that the `PREFIX` instead of ``"PREFIX"` is prefixed to
+elements.  To avoid this situation, the outer double quotations might
+be removed, but this has even another problem of the pathname
+expansions and `IFS`.
+
+Specifically for prefixing and suffixing, we may instead use
+`_comp_compgen -- -P prefix` and `_comp_compgen -- -S suffix`.
+
+```bash
+# solution for prefixing
+_comp_compgen -Rv arr -- -P "$prefix" -W '"${arr[@]}"'
+```
+
+In a general case, one needs to modify each array element in a loop,
+where only the replacement is quoted.
+
+```bash
+# general solution
+for i in "${!arr[@]}"; do
+    arr[i]=${arr[i]//pat/"$rep"}
+done
+```

test/runLint

@@ -52,6 +52,9 @@ gitgrep '(?<!command)'"$cmdstart"'(grep|ls|sed|cd)(\s|$)' \
 gitgrep '(?<!command)'"$cmdstart"'awk(\s|$)' \
     'invoke awk through "_comp_awk"'
 
+#------------------------------------------------------------------------------
+# Bash pitfalls/styles/compatibilities (which are not detected by shellcheck)
+
 gitgrep '<<<' 'herestrings use temp files, use some other way'
 
 filter_out='^(test/|bash_completion\.sh)' gitgrep ' \[ ' \
@@ -61,3 +64,9 @@ gitgrep "$cmdstart"'unset [^-]' 'Explicitly specify "unset -v/-f"'
 
 gitgrep "$cmdstart"'((set|shopt)\s+[+-][a-z]+\s+posix\b|(local\s+)?POSIXLY_CORRECT\b)' \
     'fiddling with posix mode breaks keybindings with some bash versions'
+
+gitgrep '\$\{([^{}\n]|\{.*\})+/([^{}\n]|\{.*\})+/([^{}"\n]|\{.*\})*\$.*\}' \
+    '$rep of ${var/pat/$rep} needs to be double-quoted for shopt -s patsub_replacement (bash >= 5.2) [see Sec. of patsub_replacement in doc/styleguide.md]'
+
+gitgrep '"([^"\n]|\\.)*\$\{([^{}\n]|\{.*\})+/([^{}\n]|\{.*\})+/([^{}"\n]|\{.*\})*"([^{}"\n]|\{.*\})*\$.*\}' \
+    '$rep of "${var/pat/"$rep"}" should not be quoted for bash-4.2 or shopt -s compat42 (bash >= 4.3) [see Sec. of patsub_replacement in doc/styleguide.md]'