Fix `which` not handling absolute paths to a bin

This code has not been tested.

1 files changed, 20 insertions, 3 deletions

diff --git a/src/which.zig b/src/which.zig
index 9303d6503..189bbce43 100644
--- a/src/which.zig
+++ b/src/which.zig
@@ -6,15 +6,32 @@ fn isValid(buf: *[bun.MAX_PATH_BYTES]u8, segment: []const u8, bin: []const u8) ?
     std.mem.copy(u8, buf[segment.len + 1 ..], bin);
     buf[segment.len + 1 + bin.len ..][0] = 0;
     const filepath = buf[0 .. segment.len + 1 + bin.len :0];
-    // we cannot use access() here even though all we want to do now here is check it is executable
-    // directories can be considered executable
-    std.os.accessZ(filepath, std.os.X_OK) catch return null;
+    if (!checkPath(filepath)) return null;
     return @intCast(u16, filepath.len);
 }
 
+fn checkPath(filepath: [:0]const u8) bool {
+    std.os.accessZ(filepath, std.os.X_OK) catch return false;
+    return true;
+}
+
 // Like /usr/bin/which but without needing to exec a child process
 // Remember to resolve the symlink if necessary
 pub fn which(buf: *[bun.MAX_PATH_BYTES]u8, path: []const u8, cwd: []const u8, bin: []const u8) ?[:0]const u8 {
+    if (bin.len == 0) return null;
+
+    // handle absolute paths
+    if (std.fs.path.isAbsolute(bin)) {
+        std.mem.copy(u8, buf, bin);
+        buf[bin.len] = 0;
+        var binZ: [:0]u8 = buf[0..bin.len :0];
+        if (checkPath(binZ)) return binZ;
+
+        // note that directories are often executable
+        // TODO: should we return null here? What about the case where ytou have
+        //   /foo/bar/baz as a path and you're in /home/jarred?
+    }
+
     if (isValid(buf, std.mem.trimRight(u8, cwd, std.fs.path.sep_str), bin)) |len| {
         return buf[0..len :0];
     }