feat(__load_completion): check that a completion was actually set

On successful return, at least the full path to the command in question
should have a completion set.

If the command invoked was given without a path, the pathless one should
have one set, too.

Author: scop

bash_completion

@@ -2509,7 +2509,7 @@ __load_completion()
     fi
 
     # Try to resolve real path to $cmd, and make it absolute
-    local ret realcmd=
+    local ret realcmd="" origcmd=$cmd
     if _comp_realcommand "$cmd"; then
         realcmd=$ret
         cmd=${realcmd%/*}/$cmdname # basename could be an alias
@@ -2551,7 +2551,8 @@ __load_completion()
     _comp_split -F : paths "${XDG_DATA_DIRS:-/usr/local/share:/usr/share}"
     dirs+=("${paths[@]/%//bash-completion/completions}")
 
-    # For loading 3rd party completions wrapped in shopt reset
+    # Set up default $IFS in case loaded completions depend on it,
+    # as well as for $compspec invocation below.
     local IFS=$' \t\n'
 
     # Look up and source
@@ -2573,8 +2574,27 @@ __load_completion()
                     [[ $compfile == */.?(.) ]] ||
                         echo "bash_completion: $compfile: is a directory" >&2
                 elif [[ -e $compfile ]] && . "$compfile" "$cmd" "$@"; then
-                    [[ $backslash ]] && $(complete -p "$cmdname") "\\$cmdname"
-                    return 0
+                    # At least $cmd is expected to have a completion set when
+                    # we return successfully; see if it already does
+                    if compspec=$(complete -p "$cmd" 2>/dev/null); then
+                        local -a extspecs=()
+                        # $cmd is the case in which we do backslash processing
+                        [[ $backslash ]] && extspecs+=("$backslash$cmd")
+                        # If invoked without path, that one should be set, too
+                        # ...but let's not overwrite an existing one, if any
+                        [[ $origcmd != */* ]] &&
+                            ! complete -p "$origcmd" &>/dev/null &&
+                            extspecs+=("$origcmd")
+                        ((${#extspecs[*]} != 0)) && $compspec "${extspecs[@]}"
+                        return 0
+                    fi
+                    # If not, see if we got one for $cmdname
+                    if compspec=$(complete -p "$cmdname" 2>/dev/null); then
+                        # Use that for $cmd too, if we have a full path to it
+                        [[ $cmd == /* ]] && $compspec "$cmd"
+                        return 0
+                    fi
+                    # Nothing expected was set, continue lookup
                 fi
             done
         done

test/fixtures/__load_completion/prefix1/share/bash-completion/completions/cmd1

@@ -1 +1,2 @@
 echo 'cmd1: sourced from prefix1'
+complete -C true "$1"

test/fixtures/__load_completion/prefix1/share/bash-completion/completions/cmd2

@@ -1 +1,2 @@
 echo 'cmd2: sourced from prefix1'
+complete -C true "$1"

test/fixtures/__load_completion/userdir1/completions/cmd1

@@ -1 +1,2 @@
 echo 'cmd1: sourced from userdir1'
+complete -C true "$1"

test/fixtures/__load_completion/userdir2/completions/cmd2

@@ -1 +1,2 @@
 echo 'cmd2: sourced from userdir2'
+complete -C true "$1"

test/t/unit/test_unit_load_completion.py

@@ -37,12 +37,26 @@ def test_PATH_1(self, bash):
                 bash, "__load_completion cmd2", want_output=True
             )
             assert output.strip() == "cmd2: sourced from prefix1"
+            output = assert_bash_exec(
+                bash, "complete -p cmd2", want_output=True
+            )
+            assert " cmd2" in output
+            output = assert_bash_exec(
+                bash, 'complete -p "$PWD/prefix1/sbin/cmd2"', want_output=True
+            )
+            assert "/prefix1/sbin/cmd2" in output
 
     def test_cmd_path_1(self, bash):
+        assert_bash_exec(bash, "complete -r cmd1 || :", want_output=None)
         output = assert_bash_exec(
             bash, "__load_completion prefix1/bin/cmd1", want_output=True
         )
         assert output.strip() == "cmd1: sourced from prefix1"
+        output = assert_bash_exec(
+            bash, 'complete -p "$PWD/prefix1/bin/cmd1"', want_output=True
+        )
+        assert "/prefix1/bin/cmd1" in output
+        assert_bash_exec(bash, "! complete -p cmd1", want_output=None)
         output = assert_bash_exec(
             bash, "__load_completion prefix1/sbin/cmd2", want_output=True
         )