Properly extract mod name from path for legacy mod

We introduced the change to make MineMod compatible with mods that do
not have a mod.conf, but we forgot that read_conf()? will just make the
function return early in that case - and the fallback value is never
used.

This change makes it so that read_conf() is only called when a mod.conf
exists, which has the benefit that we get the legacy name resolution for
mods without mod.conf, but if there are I/O errors while reading the
config, we will still propagate them properly (same as dependencies()).

1 files changed, 19 insertions, 9 deletions

diff --git a/modderbaas/src/minemod.rs b/modderbaas/src/minemod.rs
index 6be0ab4..00acc3a 100644
--- a/modderbaas/src/minemod.rs
+++ b/modderbaas/src/minemod.rs
@@ -43,6 +43,9 @@ pub struct MineMod {
     path: PathBuf,
 }
 
+/// The name of the mod configuration file.
+const MOD_CONF: &str = "mod.conf";
+
 impl MineMod {
     /// Opens the given directory as a mod.
     pub fn open<P: AsRef<Path>>(path: P) -> Result<MineMod> {
@@ -50,7 +53,7 @@ impl MineMod {
     }
 
     fn open_path(path: &Path) -> Result<MineMod> {
-        let conf = path.join("mod.conf");
+        let conf = path.join(MOD_CONF);
         let depends = path.join("depends.txt");
         if !conf.is_file() && !depends.is_file() {
             return Err(Error::InvalidModDir(path.into()));
@@ -65,7 +68,7 @@ impl MineMod {
     }
 
     fn read_conf(&self) -> Result<HashMap<String, String>> {
-        let conf = self.path.join("mod.conf");
+        let conf = self.path.join(MOD_CONF);
         kvstore::read(&conf)
     }
 
@@ -76,12 +79,19 @@ impl MineMod {
             .file_name()
             .map(|s| s.to_str().expect("Non-UTF8 directory encountered"));
 
-        let conf = self.read_conf()?;
-        conf.get("name")
-            .map(String::as_str)
-            .or(fallback)
-            .map(Into::into)
-            .ok_or_else(|| Error::InvalidModDir(self.path.clone()))
+        // Same reasoning as dependencies()
+        if self.path.join(MOD_CONF).is_file() {
+            let conf = self.read_conf()?;
+            conf.get("name")
+                .map(String::as_str)
+                .or(fallback)
+                .map(Into::into)
+                .ok_or_else(|| Error::InvalidModDir(self.path.clone()))
+        } else {
+            fallback
+                .map(Into::into)
+                .ok_or_else(|| Error::InvalidModDir(self.path.clone()))
+        }
     }
 
     /// Returns all dependencies of this mod.
@@ -89,7 +99,7 @@ impl MineMod {
         // We could do this with Result combinators and default values, but we also don't want to
         // end up swallowing errors (like filesystem errors). Therefore, we do some basic checks
         // first and propagate the errors.
-        if self.path.join("mod.conf").is_file() {
+        if self.path.join(MOD_CONF).is_file() {
             // First try to extract dependencies from mod.conf (the new way)
             let conf = self.read_conf()?;
             if let Some(depstr) = conf.get("depends") {