Prioritize mods with higher provided versions if their main id differs

src/main/java/net/fabricmc/loader/impl/discovery/ModResolver.java

@@ -32,6 +32,7 @@
 import org.sat4j.specs.TimeoutException;
 
 import net.fabricmc.api.EnvType;
+import net.fabricmc.loader.api.Version;
 import net.fabricmc.loader.api.metadata.ModDependency;
 import net.fabricmc.loader.api.metadata.ModDependency.Kind;
 import net.fabricmc.loader.impl.discovery.ModSolver.InactiveReason;
@@ -212,6 +213,9 @@ private static List<ModCandidate> findCompatibleSet(Collection<ModCandidate> can
 		public int compare(ModCandidate a, ModCandidate b) {
 			// descending sort prio (less/earlier is higher prio):
 			// root mods first, lower id first, higher version first, less nesting first, parent cmp
+			// if the ids are different the id+version comparison will consider all id+version pairs from each mod and its provides
+			//   multiple overlaps with provides use a comparison counter to give the mod with the most version advantages priority
+			// if the ids are equal the mod versions are assumed to represent desired priorities even if provided versions disagree
 
 			if (a.isRoot()) {
 				if (!b.isRoot()) {
@@ -223,11 +227,19 @@ public int compare(ModCandidate a, ModCandidate b) {
 
 			// sort id desc
 			int idCmp = a.getId().compareTo(b.getId());
-			if (idCmp != 0) return idCmp;
 
-			// sort version desc (lower version later)
-			int versionCmp = b.getVersion().compareTo(a.getVersion());
-			if (versionCmp != 0) return versionCmp;
+			if (idCmp != 0) {
+				if (a.getProvides().isEmpty() && b.getProvides().isEmpty()) {
+					return idCmp;
+				} else {
+					int cmp = compareOverlappingIds(a, b, idCmp);
+					if (cmp != 0) return cmp;
+				}
+			} else {
+				// sort version desc (lower version later)
+				int versionCmp = b.getVersion().compareTo(a.getVersion());
+				if (versionCmp != 0) return versionCmp;
+			}
 
 			// sort nestLevel asc
 			int nestCmp = a.getMinNestLevel() - b.getMinNestLevel(); // >0 if nest(a) > nest(b)
@@ -252,6 +264,46 @@ public int compare(ModCandidate a, ModCandidate b) {
 		}
 	};
 
+	private static int compareOverlappingIds(ModCandidate a, ModCandidate b, int idCmp) {
+		assert !a.getId().equals(b.getId()); // should have been handled before
+		assert idCmp != 0;
+
+		int ret = 0; // sum of individual normalized pair comparisons, may cancel each other out
+		boolean matched = false; // whether any ids overlap, for falling back to main id comparison as if there were no provides
+
+		for (String provIdA : a.getProvides()) { // a-provides vs b
+			if (provIdA.equals(b.getId())) {
+				Version providedVersionA = a.getVersion();
+				ret += Integer.signum(b.getVersion().compareTo(providedVersionA));
+				matched = true;
+			}
+		}
+
+		for (String provIdB : b.getProvides()) {
+			if (provIdB.equals(a.getId())) { // a vs b-provides
+				Version providedVersionB = b.getVersion();
+				ret += Integer.signum(providedVersionB.compareTo(a.getVersion()));
+				matched = true;
+
+				continue;
+			}
+
+			for (String provIdA : a.getProvides()) { // a-provides vs b-provides
+				if (provIdB.equals(provIdA)) {
+					Version providedVersionA = a.getVersion();
+					Version providedVersionB = b.getVersion();
+
+					ret += Integer.signum(providedVersionB.compareTo(providedVersionA));
+					matched = true;
+
+					break;
+				}
+			}
+		}
+
+		return matched ? ret : idCmp; // idCmp is != 0, so no need to compare version
+	}
+
 	static void preselectMod(ModCandidate mod, List<ModCandidate> allModsSorted, Map<String, List<ModCandidate>> modsById,
 			Map<String, ModCandidate> selectedMods, List<ModCandidate> uniqueSelectedMods) throws ModResolutionException {
 		selectMod(mod, selectedMods, uniqueSelectedMods);