fix: add miscellaneous fixes before implementing _comp_compgen -P

bash_completion

@@ -1352,10 +1352,12 @@ _comp_delimited()
     # `show-all-if-ambiguous` on, but even that has cases where it fails
     # and the last separator including everything before it is lost.
     # https://github.com/scop/bash-completion/pull/913#issuecomment-1490140309
-    local i
-    for i in "${!COMPREPLY[@]}"; do
-        COMPREPLY[i]="$prefix${COMPREPLY[i]}"
-    done
+    if [[ $prefix ]]; then
+        local i
+        for i in "${!COMPREPLY[@]}"; do
+            COMPREPLY[i]="$prefix${COMPREPLY[i]}"
+        done
+    fi
 
     [[ $delimiter != : ]] || _comp_ltrim_colon_completions "$cur"
 }

completions/cppcheck

@@ -16,17 +16,8 @@ _comp_cmd_cppcheck()
             return
             ;;
         --enable)
-            # split comma-separated list
-            local split=""
-            if [[ $cur == ?*,* ]]; then
-                prev="${cur%,*}"
-                cur="${cur##*,}"
-                split="set"
-            fi
-            _comp_compgen -- -W 'all warning style performance portability
-                information unusedFunction missingInclude' &&
-                [[ $split ]] &&
-                _comp_compgen -Rv COMPREPLY -- -P "$prev," -W '"${COMPREPLY[@]}"'
+            _comp_delimited , -W 'all warning style performance portability
+                information unusedFunction missingInclude'
             return
             ;;
         --error-exitcode)

completions/firefox

@@ -5,7 +5,7 @@ _comp_cmd_firefox()
     local cur prev words cword was_split comp_args
     _comp_initialize -s -- "$@" || return
 
-    [[ $cur == -MOZ_LOG*=* ]] && prev=${cur%%=*} cur=${cur#*=}
+    [[ ! $was_split && $cur == -MOZ_LOG*=* ]] && prev=${cur%%=*} cur=${cur#*=}
 
     case $prev in
         --help | --version | --display | --UILocale | -MOZ_LOG | --new-window | --new-tab | \

completions/make

@@ -110,9 +110,9 @@ _comp_cmd_make()
     elif [[ $cur == *=* ]]; then
         prev=${cur%%=*}
         cur=${cur#*=}
-        local diropt
+        local diropt=""
         [[ ${prev,,} == *dir?(ectory) ]] && diropt=-d
-        _comp_compgen_filedir $diropt
+        _comp_compgen_filedir ${diropt:+"$diropt"}
     else
         # before we check for makefiles, see if a path was specified
         # with -C/--directory

completions/openssl

@@ -32,9 +32,9 @@ _comp_cmd_openssl__compgen_digests()
         "$1" dgst -h 2>&1 |
             _comp_awk '/^-.*[ \t]to use the .* message digest algorithm/ { print $1 }'
     )"
-    _comp_compgen -ac "${cur#-}" split -P "-" -- "$("$1" help 2>&1 |
+    _comp_compgen_split -- "$("$1" help 2>&1 |
         command sed -ne '/^Message Digest commands/,/^[[:space:]]*$/p' |
-        command sed -e 1d)"
+        command sed -e '1d;s/^/-/')"
 }
 
 _comp_cmd_openssl()

completions/strings

@@ -38,8 +38,8 @@ _comp_cmd_strings()
         [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
         return
     elif [[ $cur == @* ]]; then
-        _comp_compgen -c "${cur:1}" filedir
-        COMPREPLY=("${COMPREPLY[@]/#/@}")
+        _comp_compgen -c "${cur:1}" filedir &&
+            COMPREPLY=("${COMPREPLY[@]/#/@}")
         return
     fi
 

completions/tshark

@@ -2,7 +2,7 @@
 
 _comp_cmd_tshark()
 {
-    local cur prev words cword comp_args prefix
+    local cur prev words cword comp_args prefix=""
     _comp_initialize -n : -- "$@" || return
 
     case $cur in

doc/api-and-naming.md

@@ -172,7 +172,8 @@ The exit status is implementation-defined.
 
 - The `_comp_compgen -- COMPGEN_ARGS` returns whether there is at least one
   completion.  This is useful when one wants to reuse the array content with
-  `"${tmp[@]}"` avoiding `nounset` error.
+  `"${tmp[@]}"` avoiding `nounset` error in Bash <= 4.3 for an empty array
+  `tmp`.
 - Some use other rules for the exit status. E.g., `help` and `usage` return
   whether there were options *before* filtering by cur. This is used for
   `_comp_compgen_help || _comp_compgen_usage`.
@@ -206,8 +207,8 @@ in `_comp_compgen_mygen1`.
 _comp_compgen_mygen1()
 {
     local -a arr=(1 2 3)
-    _comp_compgen -av arr -- -W '4 5 6'
-    _comp_compgen_set "${arr[@]/#p}"
+    _comp_compgen -av arr -- -W '4 5 6' &&
+      _comp_compgen_set "${arr[@]/#p}"
 }
 
 _comp_compgen -v arr mygen1 # fails to get the result in array `arr`
@@ -222,8 +223,8 @@ assigning the final result.
 _comp_compgen_mygen1()
 {
     local -a arr=(1 2 3)
-    _comp_compgen -av arr -- -W '4 5 6'
-    _comp_compgen -U arr set "${arr[@]/#p}"
+    _comp_compgen -av arr -- -W '4 5 6' &&
+      _comp_compgen -U arr set "${arr[@]/#p}"
 }
 ```
 

doc/styleguide.md

@@ -111,6 +111,16 @@ E.g. write `${foo[bar]}`, not `${foo[$bar]}`, and similarly `${foo[bar+1]}`
 vs `${foo[((bar+1))]}` or `${foo[$((bar+1))]}`, `${foo[--i]}` vs
 `${foo[((--i))]}`.
 
+## `((${#array[@]})) && cmd "${array[@]}"`
+
+When one uses the array expansion of the form `"${array[@]}"` or `${array[*]}`,
+please make sure that the `array` is not empty.  This is because of a strange
+behavior of Bash <= 4.3, where `${array[@]}` and `${array[*]}` fail for the
+`nounset` error when `array` is an empty array.  It can be explicitly tested
+with `((${#array[@]}))`, or the exit status of `_comp_compgen` that assigned
+values to the array can be used (when the generator is designed to return the
+appropriate exit status).
+
 ## Loop variable names
 
 Use `i`, `j`, `k` for loop-local indices; `n` and `m` for lengths; some other