From 435984bffda225ee923aa2c9fdbbf730d7719f74 Mon Sep 17 00:00:00 2001
From: Sebastian Thiel <sebastian.thiel@icloud.com>
Date: Thu, 23 Jan 2025 20:37:24 +0100
Subject: [PATCH] feat: add `Preprae::with_quoted_command()` (#1799)

That way it's possible to execute shell commands with spaces in their paths, for example.
---
 Cargo.lock                   |  1 +
 gix-command/Cargo.toml       |  1 +
 gix-command/src/lib.rs       | 18 +++++++++++++
 gix-command/tests/command.rs | 52 ++++++++++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index c2948482fc2..d022dc163a6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1576,6 +1576,7 @@ version = "0.4.1"
 dependencies = [
  "bstr",
  "gix-path 0.10.14",
+ "gix-quote 0.4.15",
  "gix-testtools",
  "gix-trace 0.1.12",
  "shell-words",
diff --git a/gix-command/Cargo.toml b/gix-command/Cargo.toml
index a8c607c6b55..e81cfedb4be 100644
--- a/gix-command/Cargo.toml
+++ b/gix-command/Cargo.toml
@@ -17,6 +17,7 @@ doctest = false
 [dependencies]
 gix-trace = { version = "^0.1.12", path = "../gix-trace" }
 gix-path = { version = "^0.10.14", path = "../gix-path" }
+gix-quote = { version = "^0.4.15", path = "../gix-quote" }
 
 bstr = { version = "1.5.0", default-features = false, features = ["std", "unicode"] }
 shell-words = "1.0"
diff --git a/gix-command/src/lib.rs b/gix-command/src/lib.rs
index d92d366d58c..431ca3ae56b 100644
--- a/gix-command/src/lib.rs
+++ b/gix-command/src/lib.rs
@@ -28,6 +28,9 @@ pub struct Prepare {
     pub env: Vec<(OsString, OsString)>,
     /// If `true`, we will use `shell_program` or `sh` to execute the `command`.
     pub use_shell: bool,
+    /// If `true`, `command` is assumed to be a command or path to the program to execute, and it will be shell-quoted
+    /// to assure it will be executed as is and without splitting across whitespace.
+    pub quote_command: bool,
     /// The name or path to the shell program to use instead of `sh`.
     pub shell_program: Option<OsString>,
     /// If `true` (default `true` on windows and `false` everywhere else)
@@ -119,6 +122,15 @@ mod prepare {
             self.use_shell = true;
             self
         }
+
+        /// If  [`with_shell()`](Self::with_shell()) is set, then quote the command to assure its path is left intact.
+        ///
+        /// Note that this should not be used if the command is a script - quoting is only the right choice if it's known to be a program path.
+        pub fn with_quoted_command(mut self) -> Self {
+            self.quote_command = true;
+            self
+        }
+
         /// Set the name or path to the shell `program` to use if a shell is to be used, to avoid using the default shell which is `sh`.
         pub fn with_shell_program(mut self, program: impl Into<OsString>) -> Self {
             self.shell_program = Some(program.into());
@@ -236,6 +248,11 @@ mod prepare {
                         cmd.arg("-c");
                         if !prep.args.is_empty() {
                             if prep.command.to_str().map_or(true, |cmd| !cmd.contains("$@")) {
+                                if prep.quote_command {
+                                    if let Ok(command) = gix_path::os_str_into_bstr(&prep.command) {
+                                        prep.command = gix_path::from_bstring(gix_quote::single(command)).into();
+                                    }
+                                }
                                 prep.command.push(" \"$@\"");
                             } else {
                                 gix_trace::debug!(
@@ -458,6 +475,7 @@ pub fn prepare(cmd: impl Into<OsString>) -> Prepare {
         args: Vec::new(),
         env: Vec::new(),
         use_shell: false,
+        quote_command: false,
         allow_manual_arg_splitting: cfg!(windows),
     }
 }
diff --git a/gix-command/tests/command.rs b/gix-command/tests/command.rs
index 8dde360a420..83326b3bbd6 100644
--- a/gix-command/tests/command.rs
+++ b/gix-command/tests/command.rs
@@ -351,6 +351,44 @@ mod prepare {
         );
     }
 
+    #[test]
+    fn quoted_command_without_argument_splitting() {
+        let cmd = std::process::Command::from(
+            gix_command::prepare("ls")
+                .arg("--foo=a b")
+                .command_may_be_shell_script_disallow_manual_argument_splitting()
+                .with_shell()
+                .with_quoted_command(),
+        );
+        assert_eq!(
+            format!("{cmd:?}"),
+            quoted(&[SH, "-c", "\\'ls\\' \\\"$@\\\"", "--", "--foo=a b"]),
+            "looks strange thanks to debug printing, but is the right amount of quotes actually"
+        );
+    }
+
+    #[test]
+    fn quoted_windows_command_without_argument_splitting() {
+        let cmd = std::process::Command::from(
+            gix_command::prepare("C:\\Users\\O'Shaughnessy\\with space.exe")
+                .arg("--foo='a b'")
+                .command_may_be_shell_script_disallow_manual_argument_splitting()
+                .with_shell()
+                .with_quoted_command(),
+        );
+        assert_eq!(
+            format!("{cmd:?}"),
+            quoted(&[
+                SH,
+                "-c",
+                "\\'C:\\\\Users\\\\O\\'\\\\\\'\\'Shaughnessy\\\\with space.exe\\' \\\"$@\\\"",
+                "--",
+                "--foo=\\'a b\\'"
+            ]),
+            "again, a lot of extra backslashes, but it's correct outside of the debug formatting"
+        );
+    }
+
     #[test]
     fn single_and_complex_arguments_will_not_auto_split_on_special_characters() {
         let cmd = std::process::Command::from(
@@ -388,6 +426,20 @@ mod prepare {
             We deal with it by not doubling the '$@' argument, which seems more flexible."
         );
     }
+
+    #[test]
+    fn script_with_dollar_at_has_no_quoting() {
+        let cmd = std::process::Command::from(
+            gix_command::prepare("echo \"$@\" >&2")
+                .command_may_be_shell_script()
+                .with_quoted_command()
+                .arg("store"),
+        );
+        assert_eq!(
+            format!("{cmd:?}"),
+            format!(r#""{SH}" "-c" "echo \"$@\" >&2" "--" "store""#)
+        );
+    }
 }
 
 mod spawn {