fix: compute relative path for source dirs (#157)

I misread the code and thought that we pass the recipe dir as relative path.
Instead it's the source that can be relative and needs to be turned into an absolute path.

Author: Hofer-Julian

crates/pixi-build-rattler-build/src/protocol.rs

@@ -370,11 +370,6 @@ fn build_input_globs(
     // Always add the current directory of the package to the globs
     let mut input_globs = vec!["*/**".to_string()];
 
-    // TODO: Remove this condition when working on https://github.com/prefix-dev/pixi/issues/3785
-    if !source.is_absolute() {
-        return Ok(input_globs);
-    }
-
     // Get parent directory path
     let parent = if source.is_file() {
         // use the parent path as glob
@@ -386,6 +381,11 @@ fn build_input_globs(
     // If there are sources add them to the globs as well
     if let Some(package_sources) = package_sources {
         for source in package_sources {
+            let source = if source.is_absolute() {
+                source
+            } else {
+                parent.join(source)
+            };
             let source_glob = relative_path_joined(&parent, &source)?;
             if source.is_dir() {
                 input_globs.push(format!("{}/**", source_glob));
@@ -718,4 +718,25 @@ mod tests {
         // The relative path from source_dir to package_source_dir should be "../pkgsrc/**"
         assert_eq!(globs, vec!["*/**", "../pkgsrc/**"]);
     }
+
+    #[test]
+    fn test_build_input_globs_relative_source() {
+        use std::fs;
+        use std::path::PathBuf;
+        use tempfile::tempdir;
+
+        // Create a temp directory to act as the base
+        let base_dir = tempdir().unwrap();
+        let base_path = base_dir.path();
+
+        // Case: source is a directory, package_sources contains a relative path
+        let rel_dir = PathBuf::from("rel_folder");
+        let abs_rel_dir = base_path.join(&rel_dir);
+        fs::create_dir_all(&abs_rel_dir).unwrap();
+
+        // Call build_input_globs with base_path as source, and rel_dir as package source (relative)
+        let globs = super::build_input_globs(base_path, Some(vec![rel_dir.clone()])).unwrap();
+        // The relative path from base_path to rel_dir should be "rel_folder/**"
+        assert_eq!(globs, vec!["*/**", "rel_folder/**"]);
+    }
 }