BUGFIX: bracket line search would throw a pass condition when step le…

…ngth exceeded safeguard value. This was a holdover bug from legacy seisflows and led to line searches completing even if misfit was not reduced. it would not have been encountered very often but on the chance that it was, a model would be passed that did not satisfy line search stop conditions

seisflows/plugins/line_search/bracket.py

@@ -201,22 +201,19 @@ def calculate_step_length(self):
             alpha = None
             status = "FAIL"
 
-        # Apply optional step length safeguard
-        if alpha is not None:
+        # Apply optional step length safeguard to step length
+        if status == "TRY":
             if alpha > self.step_len_max and step_count == 0:
                 alpha = 0.618034 * self.step_len_max
                 logger.info(f"try: applying initial step length "
                             f"safegaurd as alpha has exceeded maximum step "
                             f"length, alpha_new={alpha:.2E}")
-                status = "TRY"
             # Stop because safeguard prevents us from going further
-            # TODO Why is this passing? should status not be carried over?
             elif alpha > self.step_len_max:
                 alpha = self.step_len_max
-                logger.info(f"try: applying initial step length "
-                            f"safegaurd as alpha has exceeded maximum step "
-                            f"length, alpha_new={alpha:.2E}")
-                status = "PASS"
+                logger.info(f"try: applying step length safegaurd as alpha has "
+                            f"exceeded maximum allowable step length, "
+                            f"alpha_new={alpha:.2E}")
 
         return alpha, status