fix(java,rsync,ssh): complete syntactically incomplete cur

#1255 (comment)

Author: akinomyoga

bash_completion

@@ -251,6 +251,28 @@ _comp_dequote()
     fi
 }
 
+# Try to reconstruct an incomplete word and apply _comp_dequote.
+# @param    $1  String to be expanded.  The same as _comp_dequote, but
+#               incomplete backslash, single quotation, and double quotation
+#               are allowed.
+# @var[out] REPLY  Result.  The same as _comp_dequoet.
+# @since 2.17
+_comp_dequote_incomplete()
+{
+    local _word=${1-}
+    if ! [[ $_word =~ $_comp_dequote__regex_safe_word ]]; then
+        # shellcheck disable=SC1003
+        if [[ ${_word%'\'} =~ $_comp_dequote__regex_safe_word ]]; then
+            _word=${_word%'\'}
+        elif [[ $_word\' =~ $_comp_dequote__regex_safe_word ]]; then
+            _word=$_word\'
+        elif [[ $_word\" =~ $_comp_dequote__regex_safe_word ]]; then
+            _word=$_word\"
+        fi
+    fi
+    _comp_dequote "$_word"
+}
+
 # Unset the given variables across a scope boundary. Useful for unshadowing
 # global scoped variables. Note that simply calling unset on a local variable
 # will not unshadow the global variable. Rather, the result will be a local

completions/java

@@ -114,7 +114,7 @@ _comp_cmd_java__packages()
     local -a sourcepaths=("${REPLY[@]}")
 
     local REPLY
-    _comp_dequote "$cur"
+    _comp_dequote_incomplete "$cur"
     local cur_val=${REPLY-}
 
     # convert package syntax to path syntax

completions/ssh

@@ -534,7 +534,7 @@ _comp_xfunc_scp_compgen_remote_files()
         # unescape (3 backslashes to 1 for chars we escaped)
         REPLY=$(command sed -e 's/\\\\\\\('"$_comp_cmd_scp__path_esc"'\)/\\\1/g' <<<"$REPLY")
     fi
-    _comp_dequote "$REPLY"
+    _comp_dequote_incomplete "$REPLY"
     local cur_val=${REPLY-}
 
     local _userhost=${cur_val%%:*}
@@ -577,7 +577,7 @@ _comp_xfunc_scp_compgen_local_files()
     fi
 
     local REPLY
-    _comp_dequote "$cur"
+    _comp_dequote_incomplete "$cur"
     local cur_val=${REPLY-}
 
     local files

test/fixtures/scp/local_path/backslash-a b.txt

@@ -28,7 +28,13 @@ def test_basic(self, hosts, completion):
                     )
                 ),
                 # Local filenames
-                ["bin/", "config", "known_hosts", r"spaced\ \ conf"],
+                [
+                    "bin/",
+                    "config",
+                    "known_hosts",
+                    "local_path/",
+                    r"spaced\ \ conf",
+                ],
             )
         )
         assert completion == expected
@@ -48,7 +54,13 @@ def test_basic_spaced_conf(self, hosts, completion):
                     )
                 ),
                 # Local filenames
-                ["bin/", "config", "known_hosts", r"spaced\ \ conf"],
+                [
+                    "bin/",
+                    "config",
+                    "known_hosts",
+                    "local_path/",
+                    r"spaced\ \ conf",
+                ],
             )
         )
         assert completion == expected
@@ -115,6 +127,19 @@ def test_remote_path_with_spaces(self, bash):
         assert_bash_exec(bash, "unset -f ssh")
         assert completion == r"\\\ in\\\ filename.txt"
 
+    def test_remote_path_with_backslash(self, bash):
+        assert_bash_exec(
+            bash, "ssh() { printf '%s\\n' 'abc def.txt' 'abc\ def.txt'; }"
+        )
+        completion = assert_complete(bash, "scp remote_host:abc\\")
+        assert_bash_exec(bash, "unset -f ssh")
+
+        # Note: The number of backslash escaping differs depending on the scp
+        # version.
+        assert completion == sorted(
+            [r"abc\ def.txt", r"abc\\\ def.txt"]
+        ) or completion == sorted([r"abc\\\ def.txt", r"abc\\\\\\\ def.txt"])
+
     def test_xfunc_remote_files(self, bash):
         with bash_env_saved(bash) as bash_env:
             bash_env.save_variable("COMPREPLY")
@@ -193,3 +218,9 @@ def test_local_path_with_spaces_1(self, completion):
     @pytest.mark.complete("scp spaced\\ ", cwd="scp")
     def test_local_path_with_spaces_2(self, completion):
         assert completion == "\\ conf"
+
+    @pytest.mark.complete("scp backslash-a\\", cwd="scp/local_path")
+    def test_local_path_backslash(self, completion):
+        assert completion == sorted(
+            [r"backslash-a\ b.txt", r"backslash-a\\\ b.txt"]
+        )