Adjust unknown licenses heuristics

Signed-off-by: Ayan Sinha Mahapatra <ayansmahapatra@gmail.com>

Author: AyanSinhaMahapatra

src/licensedcode/detection.py

@@ -784,7 +784,6 @@ def get_detected_license_expression(matches, analysis, post_scan=False):
             logger_debug(f'analysis {DetectionCategory.UNKNOWN_MATCH.value}')
         matches_for_expression = matches
         detection_log.append(DetectionRule.UNKNOWN_MATCH.value)
-        return detection_log, combined_expression
 
     elif analysis == DetectionCategory.LICENSE_CLUES.value:
         if TRACE_ANALYSIS:
@@ -970,6 +969,11 @@ def analyze_detection(license_matches, package_license=False):
     elif is_correct_detection(license_matches):
         return DetectionCategory.PERFECT_DETECTION.value
 
+    # Case where even though the matches have perfect coverage, they have
+    # matches with `unknown` rule identifiers
+    elif has_unknown_matches(license_matches):
+        return DetectionCategory.UNKNOWN_MATCH.value
+    
     elif is_license_clues(license_matches):
         return DetectionCategory.LICENSE_CLUES.value
 
@@ -984,11 +988,6 @@ def analyze_detection(license_matches, package_license=False):
     elif has_extra_words(license_matches):
         return DetectionCategory.EXTRA_WORDS.value
 
-    # Case where even though the matches have perfect coverage, they have
-    # matches with `unknown` rule identifiers
-    elif has_unknown_matches(license_matches):
-        return DetectionCategory.UNKNOWN_MATCH.value
-
     # Cases where Match Coverage is a perfect 100 for all matches
     else:
         return DetectionCategory.PERFECT_DETECTION.value

tests/packagedcode/data/license_detection/reference-to-package/samba.expected.json

@@ -195,7 +195,7 @@
         {
           "license_expression": "gpl-2.0-plus AND free-unknown AND gpl-1.0-plus",
           "detection_log": [
-            "not-combined"
+            "unknown-match"
           ],
           "matches": [
             {
@@ -966,7 +966,7 @@
         {
           "license_expression": "gpl-2.0-plus AND free-unknown AND gpl-1.0-plus",
           "detection_log": [
-            "not-combined"
+            "unknown-match"
           ],
           "matches": [
             {
@@ -1711,7 +1711,7 @@
             {
               "license_expression": "gpl-2.0-plus AND free-unknown AND gpl-1.0-plus",
               "detection_log": [
-                "not-combined"
+                "unknown-match"
               ],
               "matches": [
                 {
@@ -2468,7 +2468,7 @@
             {
               "license_expression": "gpl-2.0-plus AND free-unknown AND gpl-1.0-plus",
               "detection_log": [
-                "not-combined"
+                "unknown-match"
               ],
               "matches": [
                 {