Fix reverse-depends -b crash on packages that b-d on themselves (Closes: #1087760).

debian/changelog

@@ -1,7 +1,12 @@
 ubuntu-dev-tools (0.204) UNRELEASED; urgency=medium
 
+  [ Simon Quigley ]
   * Update Standards-Version to 4.7.1, no changes needed.
 
+  [ Julien Plissonneau Duquène ]
+  * Fix reverse-depends -b crash on packages that b-d on themselves
+    (Closes: #1087760).
+
  -- Simon Quigley <tsimonq2@debian.org>  Mon, 24 Feb 2025 18:26:09 -0600
 
 ubuntu-dev-tools (0.203) unstable; urgency=medium

reverse-depends

@@ -183,7 +183,7 @@ def display_verbose(package, values):
         Logger.info("No reverse dependencies found")
         return
 
-    def log_package(values, package, arch, dependency, offset=0):
+    def log_package(values, package, arch, dependency, visited, offset=0):
         line = f"{'  ' * offset}* {package}"
         if all_archs and set(arch) != all_archs:
             line += f" [{' '.join(sorted(arch))}]"
@@ -192,6 +192,9 @@ def display_verbose(package, values):
                 line += " " * (30 - len(line))
                 line += f"  (for {dependency})"
         Logger.info(line)
+        if package in visited:
+            return
+        visited = visited.copy().add(package)
         data = values.get(package)
         if data:
             offset = offset + 1
@@ -202,6 +205,7 @@ def display_verbose(package, values):
                         rdep["Package"],
                         rdep.get("Architectures", all_archs),
                         rdep.get("Dependency"),
+                        visited,
                         offset,
                     )
 
@@ -223,6 +227,7 @@ def display_verbose(package, values):
                 rdep["Package"],
                 rdep.get("Architectures", all_archs),
                 rdep.get("Dependency"),
+                {package},
             )
         Logger.info("")