From 2b5755aa8a3732694b30367eb0cbb8db2eff47d8 Mon Sep 17 00:00:00 2001
From: Jeremy Cantrell <jmcantrell@gmail.com>
Date: Sun, 16 Oct 2022 04:33:08 -0500
Subject: [PATCH] An attempt at safer message passing.

---
 src/app.rs              |  11 ++++
 src/init.lua            | 118 +++++++++++++++++++++-------------------
 src/lib.rs              |   1 +
 src/msg/in_/external.rs |   3 +-
 src/newlines.rs         |  79 +++++++++++++++++++++++++++
 src/pipe.rs             |   6 +-
 src/runner.rs           |   9 +--
 7 files changed, 159 insertions(+), 68 deletions(-)
 create mode 100644 src/newlines.rs

diff --git a/src/app.rs b/src/app.rs
index a21d5af..57e2443 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -15,6 +15,7 @@ pub use crate::msg::in_::ExternalMsg;
 pub use crate::msg::in_::InternalMsg;
 pub use crate::msg::in_::MsgIn;
 pub use crate::msg::out::MsgOut;
+use crate::newlines::unescape_string;
 pub use crate::node::Node;
 pub use crate::node::ResolvedNode;
 pub use crate::pipe::Pipe;
@@ -174,6 +175,7 @@ pub struct App {
     pub mode: Mode,
     pub layout: Layout,
     pub input: InputBuffer,
+    pub input_unescaped: String,
     pub pid: u32,
     pub session_path: String,
     pub pipe: Pipe,
@@ -308,6 +310,7 @@ impl App {
             mode,
             layout,
             input,
+            input_unescaped: Default::default(),
             pid,
             session_path: session_path.clone(),
             pipe: Pipe::from_session_path(&session_path)?,
@@ -554,6 +557,14 @@ impl App {
                 }
             });
 
+        self.input_unescaped = unescape_string(
+            &self.input
+                .buffer
+                .as_ref()
+                .map(|i| i.value().to_string())
+                .unwrap_or_default(),
+        )?;
+
         for msg in msgs {
             self = self.enqueue(Task::new(MsgIn::External(msg), Some(key)));
         }
diff --git a/src/init.lua b/src/init.lua
index e778716..fc15020 100644
--- a/src/init.lua
+++ b/src/init.lua
@@ -1156,7 +1156,7 @@ xplr.config.modes.builtin.default = {
           {
             BashExecSilently = [===[
               NAME=$(basename "${XPLR_FOCUS_PATH:?}")
-              echo SetInputBuffer: "'${NAME:?}'" >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "SetInputBuffer: %s\0" "${NAME:?}" >> "${XPLR_PIPE_MSG_IN:?}"
             ]===],
           },
         },
@@ -1169,7 +1169,7 @@ xplr.config.modes.builtin.default = {
           {
             BashExecSilently = [===[
               NAME=$(basename "${XPLR_FOCUS_PATH:?}")
-              echo SetInputBuffer: "'${NAME:?}'" >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "SetInputBuffer: %s\0" "${NAME:?}" >> "${XPLR_PIPE_MSG_IN:?}"
             ]===],
           },
         },
@@ -1205,7 +1205,7 @@ xplr.config.modes.builtin.default = {
         messages = {
           {
             BashExecSilently = [===[
-              echo ChangeDirectory: "'${HOME:?}'" >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ChangeDirectory: %s\0" "${HOME:?}" >> "${XPLR_PIPE_MSG_IN:?}"
             ]===],
           },
         },
@@ -1364,9 +1364,9 @@ xplr.config.modes.builtin.go_to_path = {
           {
             BashExecSilently = [===[
               if [ -d "$XPLR_INPUT_BUFFER" ]; then
-                echo ChangeDirectory: "'$XPLR_INPUT_BUFFER'" >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "ChangeDirectory: %s\0" "$XPLR_INPUT_BUFFER" >> "${XPLR_PIPE_MSG_IN:?}"
               elif [ -e "$XPLR_INPUT_BUFFER" ]; then
-                echo FocusPath: "'$XPLR_INPUT_BUFFER'" >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "FocusPath: %s\0" "$XPLR_INPUT_BUFFER" >> "${XPLR_PIPE_MSG_IN:?}"
               fi
             ]===],
           },
@@ -1400,15 +1400,15 @@ xplr.config.modes.builtin.selection_ops = {
         messages = {
           {
             BashExec = [===[
-              (while IFS= read -r line; do
-                if cp -vr -- "${line:?}" ./; then
-                  echo LogSuccess: "'$line copied to $PWD'" >> "${XPLR_PIPE_MSG_IN:?}"
-                else
-                  echo LogError: "'Failed to copy $line to $PWD'" >> "${XPLR_PIPE_MSG_IN:?}"
-                fi
+              (while IFS= read -r -d '' line; do
+              if cp -vr -- "${line:?}" ./; then
+                printf "LogSuccess: %s\0" "$line copied to $PWD" >> "${XPLR_PIPE_MSG_IN:?}"
+              else
+                printf "LogError: %s\0" "Failed to copy $line to $PWD" >> "${XPLR_PIPE_MSG_IN:?}"
+              fi
               done < "${XPLR_PIPE_SELECTION_OUT:?}")
-              echo ExplorePwdAsync >> "${XPLR_PIPE_MSG_IN:?}"
-              echo ClearSelection >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ExplorePwdAsync\0" >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ClearSelection\0" >> "${XPLR_PIPE_MSG_IN:?}"
               read -p "[enter to continue]"
             ]===],
           },
@@ -1420,14 +1420,14 @@ xplr.config.modes.builtin.selection_ops = {
         messages = {
           {
             BashExec = [===[
-              (while IFS= read -r line; do
-                if mv -v -- "${line:?}" ./; then
-                  echo LogSuccess: "'$line moved to $PWD'" >> "${XPLR_PIPE_MSG_IN:?}"
-                else
-                  echo LogError: "'Failed to move $line to $PWD'" >> "${XPLR_PIPE_MSG_IN:?}"
-                fi
+              (while IFS= read -r -d '' line; do
+              if mv -v -- "${line:?}" ./; then
+                printf "LogSuccess: %s\0" "$line moved to $PWD" >> "${XPLR_PIPE_MSG_IN:?}"
+              else
+                printf "LogError: %s\0" "Failed to move $line to $PWD" >> "${XPLR_PIPE_MSG_IN:?}"
+              fi
               done < "${XPLR_PIPE_SELECTION_OUT:?}")
-              echo ExplorePwdAsync >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ExplorePwdAsync\0" >> "${XPLR_PIPE_MSG_IN:?}"
               read -p "[enter to continue]"
             ]===],
           },
@@ -1452,12 +1452,12 @@ xplr.config.modes.builtin.selection_ops = {
                   elif command -v open; then
                   OPENER=open
                 else
-                  echo LogError: '$OPENER not found' >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogError: %s\0" "$OPENER not found" >> "${XPLR_PIPE_MSG_IN:?}"
                   exit 1
                 fi
               fi
-              (while IFS= read -r line; do
-                $OPENER "${line:?}" > /dev/null 2>&1
+              (while IFS= read -r -d '' line; do
+              $OPENER "${line:?}" > /dev/null 2>&1
               done < "${XPLR_PIPE_RESULT_OUT:?}")
             ]===],
           },
@@ -1518,12 +1518,12 @@ xplr.config.modes.builtin.create_directory = {
               PTH="$XPLR_INPUT_BUFFER"
               if [ "${PTH}" ]; then
                 mkdir -p -- "${PTH:?}" \
-                && echo SetInputBuffer: "''" >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo ExplorePwd >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo LogSuccess: "'$PTH created'" >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo FocusPath: "'$PTH'" >> "${XPLR_PIPE_MSG_IN:?}"
+                && printf "SetInputBuffer: ''\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "ExplorePwd\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "LogSuccess: %s\0" "$PTH created" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "FocusPath: %s\0" "$PTH" >> "${XPLR_PIPE_MSG_IN:?}"
               else
-                echo PopMode >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "PopMode\0" >> "${XPLR_PIPE_MSG_IN:?}"
               fi
             ]===],
           },
@@ -1561,12 +1561,12 @@ xplr.config.modes.builtin.create_file = {
               if [ "$PTH" ]; then
                 mkdir -p -- "$(dirname $PTH)" \
                 && touch -- "$PTH" \
-                && echo SetInputBuffer: "''" >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo LogSuccess: "'$PTH created'" >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo ExplorePwd >> "${XPLR_PIPE_MSG_IN:?}" \
-                && echo FocusPath: "'$PTH'" >> "${XPLR_PIPE_MSG_IN:?}"
+                && printf "SetInputBuffer: ''\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "LogSuccess: %s\0" "$PTH created" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "ExplorePwd\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                && printf "FocusPath: %s\0" "$PTH" >> "${XPLR_PIPE_MSG_IN:?}"
               else
-                echo PopMode >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "PopMode\0" >> "${XPLR_PIPE_MSG_IN:?}"
               fi
             ]===],
           },
@@ -1668,7 +1668,7 @@ xplr.config.modes.builtin.go_to = {
                   elif command -v open; then
                   OPENER=open
                 else
-                  echo LogError: '$OPENER not found' >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogError: %s\0" "$OPENER not found" >> "${XPLR_PIPE_MSG_IN:?}"
                   exit 1
                 fi
               fi
@@ -1704,12 +1704,12 @@ xplr.config.modes.builtin.rename = {
               SRC="${XPLR_FOCUS_PATH:?}"
               TARGET="${XPLR_INPUT_BUFFER:?}"
               if [ -e "${TARGET:?}" ]; then
-                echo LogError: "'$TARGET already exists'" >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "LogError: %s\0" "$TARGET already exists" >> "${XPLR_PIPE_MSG_IN:?}"
               else
                 mv -- "${SRC:?}" "${TARGET:?}" \
-                  && echo ExplorePwd >> "${XPLR_PIPE_MSG_IN:?}" \
-                  && echo FocusPath: "'$TARGET'" >> "${XPLR_PIPE_MSG_IN:?}" \
-                  && echo LogSuccess: "'$SRC renamed to $TARGET'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  && printf "ExplorePwd\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                  && printf "FocusPath: %s\0" "$TARGET" >> "${XPLR_PIPE_MSG_IN:?}" \
+                  && printf "LogSuccess: %s\0" "$SRC renamed to $TARGET" >> "${XPLR_PIPE_MSG_IN:?}"
               fi
             ]===],
           },
@@ -1746,12 +1746,12 @@ xplr.config.modes.builtin.duplicate_as = {
               SRC="${XPLR_FOCUS_PATH:?}"
               TARGET="${XPLR_INPUT_BUFFER:?}"
               if [ -e "${TARGET:?}" ]; then
-                echo LogError: "'$TARGET already exists'" >> "${XPLR_PIPE_MSG_IN:?}"
+                printf "LogError: %s\0" "$TARGET already exists" >> "${XPLR_PIPE_MSG_IN:?}"
               else
                 cp -r -- "${SRC:?}" "${TARGET:?}" \
-                  && echo ExplorePwd >> "${XPLR_PIPE_MSG_IN:?}" \
-                  && echo FocusPath: "'$TARGET'" >> "${XPLR_PIPE_MSG_IN:?}" \
-                  && echo LogSuccess: "'$SRC duplicated as $TARGET'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  && printf "ExplorePwd\0" >> "${XPLR_PIPE_MSG_IN:?}" \
+                  && printf "FocusPath: %s\0" "$TARGET" >> "${XPLR_PIPE_MSG_IN:?}" \
+                  && printf "LogSuccess: %s\0" "$SRC duplicated as $TARGET" >> "${XPLR_PIPE_MSG_IN:?}"
               fi
             ]===],
           },
@@ -1779,14 +1779,14 @@ xplr.config.modes.builtin.delete = {
         messages = {
           {
             BashExec = [===[
-              (while IFS= read -r line; do
-                if rm -rfv -- "${line:?}"; then
-                  echo LogSuccess: "'$line deleted'" >> "${XPLR_PIPE_MSG_IN:?}"
-                else
-                  echo LogError: "'Failed to delete $line'" >> "${XPLR_PIPE_MSG_IN:?}"
-                fi
+              (while IFS= read -r -d '' line; do
+              if rm -rfv -- "${line:?}"; then
+                printf "LogSuccess: %s\0" "$line deleted" >> "${XPLR_PIPE_MSG_IN:?}"
+              else
+                printf "LogError: %s\0" "Failed to delete $line" >> "${XPLR_PIPE_MSG_IN:?}"
+              fi
               done < "${XPLR_PIPE_RESULT_OUT:?}")
-              echo ExplorePwdAsync >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ExplorePwdAsync\0" >> "${XPLR_PIPE_MSG_IN:?}"
               read -p "[enter to continue]"
             ]===],
           },
@@ -1798,22 +1798,22 @@ xplr.config.modes.builtin.delete = {
         messages = {
           {
             BashExec = [===[
-              (while IFS= read -r line; do
+              (while IFS= read -r -d '' line; do
               if [ -d "$line" ] && [ ! -L "$line" ]; then
                 if rmdir -v -- "${line:?}"; then
-                  echo LogSuccess: "'$line deleted'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogSuccess: %s\0" "$line deleted" >> "${XPLR_PIPE_MSG_IN:?}"
                 else
-                  echo LogError: "'Failed to delete $line'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogError: %s\0" "Failed to delete $line" >> "${XPLR_PIPE_MSG_IN:?}"
                 fi
               else
                 if rm -v -- "${line:?}"; then
-                  echo LogSuccess: "'$line deleted'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogSuccess: %s\0" "$line deleted" >> "${XPLR_PIPE_MSG_IN:?}"
                 else
-                  echo LogError: "'Failed to delete $line'" >> "${XPLR_PIPE_MSG_IN:?}"
+                  printf "LogError: %s\0" "Failed to delete $line" >> "${XPLR_PIPE_MSG_IN:?}"
                 fi
               fi
               done < "${XPLR_PIPE_RESULT_OUT:?}")
-              echo ExplorePwdAsync >> "${XPLR_PIPE_MSG_IN:?}"
+              printf "ExplorePwdAsync\0" >> "${XPLR_PIPE_MSG_IN:?}"
               read -p "[enter to continue]"
             ]===],
           },
@@ -2431,13 +2431,17 @@ end
 xplr.fn.builtin.fmt_general_table_row_cols_1 = function(m)
   local r = m.tree .. m.prefix
 
+  local function path_escape(path)
+    return string.gsub(string.gsub(path, "\\", "\\\\"), "\n", "\\n")
+  end
+
   if m.meta.icon == nil then
     r = r .. ""
   else
     r = r .. m.meta.icon .. " "
   end
 
-  r = r .. m.relative_path
+  r = r .. path_escape(m.relative_path)
 
   if m.is_dir then
     r = r .. "/"
@@ -2451,7 +2455,7 @@ xplr.fn.builtin.fmt_general_table_row_cols_1 = function(m)
     if m.is_broken then
       r = r .. "×"
     else
-      r = r .. m.symlink.absolute_path
+      r = r .. path_escape(m.symlink.absolute_path)
 
       if m.symlink.is_dir then
         r = r .. "/"
diff --git a/src/lib.rs b/src/lib.rs
index 8314c80..c1f48f8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,6 +17,7 @@ pub mod pipe;
 pub mod pwd_watcher;
 pub mod runner;
 pub mod ui;
+pub mod newlines;
 
 #[cfg(test)]
 mod tests {
diff --git a/src/msg/in_/external.rs b/src/msg/in_/external.rs
index 41ae01a..fe79969 100644
--- a/src/msg/in_/external.rs
+++ b/src/msg/in_/external.rs
@@ -3,6 +3,7 @@ use indexmap::IndexSet;
 use regex::Regex;
 use serde::{Deserialize, Serialize};
 use std::cmp::Ordering;
+use crate::newlines::escape_string;
 
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
 pub enum ExternalMsg {
@@ -1070,7 +1071,7 @@ impl TryFrom<&str> for ExternalMsg {
         if value.starts_with('!') {
             serde_yaml::from_str(value)
         } else if let Some((msg, args)) = value.split_once(' ') {
-            let msg = format!("!{} {}", msg.trim_end_matches(':'), args);
+            let msg = format!("!{} {}", msg.trim_end_matches(':'), escape_string(args));
             serde_yaml::from_str(&msg)
         } else {
             serde_yaml::from_str(value)
diff --git a/src/newlines.rs b/src/newlines.rs
new file mode 100644
index 0000000..231ba28
--- /dev/null
+++ b/src/newlines.rs
@@ -0,0 +1,79 @@
+struct UnescapedString<'a> {
+    s: std::str::Chars<'a>,
+}
+
+impl<'a> UnescapedString<'a> {
+    fn new(s: &'a str) -> Self {
+        Self { s: s.chars() }
+    }
+}
+
+impl Iterator for UnescapedString<'_> {
+    type Item = Result<char, Error>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.s.next().map(|c| match c {
+            '\\' => match self.s.next() {
+                None => Err(Error::EscapeAtEndOfString),
+                Some('n') => Ok('\n'),
+                Some('\\') => Ok('\\'),
+                Some(c) => Err(Error::UnrecognizedEscapedChar(c)),
+            },
+            c => Ok(c),
+        })
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    EscapeAtEndOfString,
+    UnrecognizedEscapedChar(char),
+}
+
+use std::fmt;
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::EscapeAtEndOfString => {
+                write!(f, "Escape character at the end of the string")
+            }
+            Error::UnrecognizedEscapedChar(c) => {
+                write!(f, "Unrecognized escaped char: '{}'", c)
+            }
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+struct EscapedString<'a> {
+    s: std::str::Chars<'a>,
+}
+
+impl<'a> EscapedString<'a> {
+    fn new(s: &'a str) -> Self {
+        Self { s: s.chars() }
+    }
+}
+
+impl Iterator for EscapedString<'_> {
+    type Item = String;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.s.next() {
+            None => None,
+            Some('\\') => Some(String::from("\\\\")),
+            Some('\n') => Some(String::from("\\n")),
+            Some(c) => Some(String::from(c)),
+        }
+    }
+}
+
+pub fn escape_string(s: &str) -> String {
+    EscapedString::new(s).collect()
+}
+
+pub fn unescape_string(s: &str) -> Result<String, Error> {
+    UnescapedString::new(s).collect()
+}
diff --git a/src/pipe.rs b/src/pipe.rs
index 0724bde..f3993f6 100644
--- a/src/pipe.rs
+++ b/src/pipe.rs
@@ -65,10 +65,12 @@ pub fn read_all(pipe: &str) -> Result<Vec<ExternalMsg>> {
     file.read_to_string(&mut in_str)?;
     file.set_len(0)?;
 
+    let delim = '\0';
+
     if !in_str.is_empty() {
         let mut msgs = vec![];
-        for msg in in_str.lines() {
-            msgs.push(msg.trim().try_into()?);
+        for msg in in_str.trim_matches(delim).split(delim) {
+            msgs.push(msg.try_into()?);
         }
         Ok(msgs)
     } else {
diff --git a/src/runner.rs b/src/runner.rs
index d1ee247..2fc5481 100644
--- a/src/runner.rs
+++ b/src/runner.rs
@@ -77,14 +77,7 @@ fn call(app: &app::App, cmd: app::Command, silent: bool) -> Result<ExitStatus> {
     Command::new(cmd.command.clone())
         .env("XPLR_APP_VERSION", app.version.clone())
         .env("XPLR_PID", &app.pid.to_string())
-        .env(
-            "XPLR_INPUT_BUFFER",
-            app.input
-                .buffer
-                .as_ref()
-                .map(|i| i.value().to_string())
-                .unwrap_or_default(),
-        )
+        .env("XPLR_INPUT_BUFFER", &app.input_unescaped)
         .env("XPLR_FOCUS_PATH", app.focused_node_str())
         .env("XPLR_FOCUS_INDEX", focus_index)
         .env("XPLR_SESSION_PATH", &app.session_path)