App.get_project_refs(): Fix multi-section results

get_project_refs() takes a list of sections to look for references in. To
now, that has never been exercised, i.e. only one section had ever been
passed in. With the introduction of pkg.recommends, that could change now,
and it has a subtle bug.

Say, a caller wants to retrieve all requires and recommends of package A
with this graph:

  A recommends B, requires nothing
  B requires C

then A, B, C should be returned, but the current implementation only
returns A and B. The cause is that every section is recursed into in
isolation, and the union of all results is returned. Since A doesn't
require anything, the requires-branch never reaches B, and C is missed.

The fix is to make __get_project_refs(), the recursing method, take a list
of sections instead of one section, and decide if it recurses deeper based
on all of its entries at every depth.

Signed-off-by: Jan Lindemann <jan@janware.com>
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v0.86.1

src/python/jw/pkg/App.py

@@ -203,7 +203,7 @@ class App(Base):
         buf: list[str],
         visited: set[str],
         spec: str,
-        section: str,
+        sections: list[str],
         key: str,
         add_self: bool,
         scope: Scope,
@@ -230,29 +230,33 @@ class App(Base):
                 f'Unmet dependency on {mod}: the -{needed_subpackage} package '
                 f'of project {name} is not installed'
             )
-        vals = self.get_value(name, section, key)
-        log(
-            DEBUG,
-            (
-                f'name={name}, section={section}, key={key}, deps={vals}, '
-                f'scope={scope.name}, visited={visited}'
-            ),
-        )
-        vals_list = vals.split(',') if vals else []
+        vals_list: list[str] = []
+        for section in sections:
+            vals = self.get_value(name, section, key)
+            log(
+                DEBUG,
+                (
+                    f'name={name}, section={section}, key={key}, deps={vals}, '
+                    f'scope={scope.name}, visited={visited}'
+                ),
+            )
+            if not vals:
+                continue
+            for val in vals.split(','):
+                val = val.strip()
+                if (len(val)) and (val not in vals_list):
+                    vals_list.append(val)
         match scope:
             case Scope.Self:
                 buf += vals_list
             case Scope.One | Scope.Subtree:
                 subscope = scope.Self if scope == Scope.One else scope
                 for val in vals_list:
-                    val = val.strip()
-                    if not (len(val)):
-                        continue
                     self.__get_project_refs(
                         buf,
                         visited,
                         val,
-                        section,
+                        sections,
                         key,
                         add_self = True,
                         scope = subscope,
@@ -559,18 +563,17 @@ class App(Base):
         if isinstance(keys, str):
             keys = [keys]
         ret: list[str] = []
-        for section in sections:
-            for key in keys:
-                visited: set[str] = set()
-                for name in projects:
-                    rr: list[str] = []
-                    self.__get_project_refs(
-                        rr, visited, name, section, key, add_self, scope, names_only
-                    )
-                    # TODO: this looks like a performance hogger
-                    for m in rr:
-                        if m not in ret:
-                            ret.append(m)
+        for key in keys:
+            visited: set[str] = set()
+            for name in projects:
+                rr: list[str] = []
+                self.__get_project_refs(
+                    rr, visited, name, sections, key, add_self, scope, names_only
+                )
+                # TODO: this looks like a performance hogger
+                for m in rr:
+                    if m not in ret:
+                        ret.append(m)
         return ret
 
     def get_libname(self, spec: str) -> str | None: