From fd1c0906224791550a94d2449da2dabde6a33cca Mon Sep 17 00:00:00 2001
From: Samuel Kogler <samuel.kogler@gmail.com>
Date: Fri, 11 Nov 2022 13:08:57 +0100
Subject: [PATCH] Fix memory leak in CRS.to_authority/CRS.list_authority

List elements were not properly disposed of when iterating the results of proj_identify. This fixes this and simplifies the cleanup logic.
---
 docs/history.rst |  1 +
 pyproj/_crs.pyx  | 35 ++++++++++++++++++-----------------
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/docs/history.rst b/docs/history.rst
index 00c6c7c69..c90485e07 100644
--- a/docs/history.rst
+++ b/docs/history.rst
@@ -8,6 +8,7 @@ Latest
 -----
 - BUG: Changed so that the setup.cfg depends on the version code in the __init__.py instead of the other way around (issuue #1155)
 - BUG: Fix :meth:`.CRS.to_cf` for Pole rotation GRIB convention (pull #1167)
+- BUG: Fix :meth:`.CRS.to_authority` memory leak (pull #1178)
 - REF: Use upper case EPSG code when creating CRS (pull #1162)
 
 3.4.0
diff --git a/pyproj/_crs.pyx b/pyproj/_crs.pyx
index 9a0157b3a..9a18db969 100644
--- a/pyproj/_crs.pyx
+++ b/pyproj/_crs.pyx
@@ -2834,15 +2834,19 @@ cdef class _CRS(Base):
         # get list of possible matching projections
         cdef PJ_OBJ_LIST *proj_list = NULL
         cdef int *c_out_confidence_list = NULL
-        cdef int num_proj_objects = -9999
+        cdef int num_proj_objects = 0
         cdef bytes b_auth_name
         cdef char *user_auth_name = NULL
         cdef int iii = 0
+        cdef PJ * proj = NULL
+        cdef const char * code
+        cdef const char * out_auth_name
 
         if auth_name is not None:
             b_auth_name = cstrencode(auth_name)
             user_auth_name = b_auth_name
 
+        authority_list = []
         out_confidence_list = []
         try:
             proj_list = proj_identify(
@@ -2854,24 +2858,16 @@ cdef class _CRS(Base):
             )
             if proj_list != NULL:
                 num_proj_objects = proj_list_get_count(proj_list)
-            if c_out_confidence_list != NULL and num_proj_objects > 0:
-                out_confidence_list = [
-                    c_out_confidence_list[iii] for iii in range(num_proj_objects)
-                ]
-        finally:
-            if c_out_confidence_list != NULL:
-                proj_int_list_destroy(c_out_confidence_list)
-            CRSError.clear()
 
-        # retrieve the best matching projection
-        cdef PJ* proj = NULL
-        cdef const char* code
-        cdef const char* out_auth_name
-        authority_list = []
-        try:
+            out_confidence_list = [
+                c_out_confidence_list[iii] for iii in range(num_proj_objects)
+            ]
+
+            # retrieve the best matching projection
             for iii in range(num_proj_objects):
                 if out_confidence_list[iii] < min_confidence:
                     continue
+
                 proj = proj_list_get(self.context, proj_list, iii)
                 code = proj_get_id_code(proj, 0)
                 out_auth_name = proj_get_id_auth_name(proj, 0)
@@ -2883,9 +2879,14 @@ cdef class _CRS(Base):
                             out_confidence_list[iii]
                         )
                     )
+                # at this point, the auth name is copied and we can release the proj object
+                proj_destroy(proj)
+                proj = NULL
         finally:
-            for iii in range(num_proj_objects):
-                proj_destroy(proj_list_get(self.context, proj_list, iii))
+            # If there was an error we have to call proj_destroy
+            # If there was none, calling it on NULL does nothing
+            proj_destroy(proj)
+            proj_int_list_destroy(c_out_confidence_list)
             proj_list_destroy(proj_list)
             CRSError.clear()
         return authority_list