Replace pointer comparisons and assignments to literal zero with NULL

While 0 is technically correct, NULL is the semantically appropriate
choice for pointers.

Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://www.postgresql.org/message-id/aS1AYnZmuRZ8g%2B5G%40ip-10-97-1-34.eu-west-3.compute.internal

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 475693b08bc5abd4024ed8cc62b1a8432498e478..efd02eb01c405f77c5d27a88a043f6cc3110c29f 100644 (file)
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -204,7 +204,7 @@ copyObjectImpl(const void *from)
 
        default:
            elog(ERROR, "unrecognized node type: %d", (int) nodeTag(from));
-           retval = 0;         /* keep compiler quiet */
+           retval = NULL;      /* keep compiler quiet */
            break;
    }
 

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 7c064cf9fbb288180380521dee24f5c03db439c4..a956db4ad27b27fcde50b40c1af7c5d91dec0a21 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -3391,7 +3391,7 @@ LaunchMissingBackgroundProcesses(void)
            Shutdown <= SmartShutdown)
        {
            WalReceiverPMChild = StartChildProcess(B_WAL_RECEIVER);
-           if (WalReceiverPMChild != 0)
+           if (WalReceiverPMChild != NULL)
                WalReceiverRequested = false;
            /* else leave the flag set, so we'll try again later */
        }

diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index b02e7fa4f18ab4660dbd604339ea394cd81e145a..b26257c0a8df4e3a680a0090e8b46462095229a3 100644 (file)
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1222,10 +1222,10 @@ pg_newlocale_from_collation(Oid collid)
         * Make sure cache entry is marked invalid, in case we fail before
         * setting things.
         */
-       cache_entry->locale = 0;
+       cache_entry->locale = NULL;
    }
 
-   if (cache_entry->locale == 0)
+   if (cache_entry->locale == NULL)
    {
        cache_entry->locale = create_pg_locale(collid, CollationCacheContext);
    }

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index af48527d436f9c5d81d492e85174e31a7468ee63..2dc90a2b8a9171ab36cdf076e345a6bfffceae2e 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -5161,7 +5161,7 @@ interval_trunc(PG_FUNCTION_ARGS)
                             errmsg("unit \"%s\" not supported for type %s",
                                    lowunits, format_type_be(INTERVALOID)),
                             (val == DTK_WEEK) ? errdetail("Months usually have fractional weeks.") : 0));
-                   result = 0;
+                   result = NULL;
            }
        }
 

diff --git a/src/interfaces/ecpg/ecpglib/prepare.c b/src/interfaces/ecpg/ecpglib/prepare.c
index 4b1ae83950679b4f5b27d01ac9cfbf9163d7f9fc..a3f51993d70bace770a6116716b76cf01ff0745f 100644 (file)
--- a/src/interfaces/ecpg/ecpglib/prepare.c
+++ b/src/interfaces/ecpg/ecpglib/prepare.c
@@ -509,7 +509,7 @@ ecpg_freeStmtCacheEntry(int lineno, int compat,
    if (entry->ecpgQuery)
    {
        ecpg_free(entry->ecpgQuery);
-       entry->ecpgQuery = 0;
+       entry->ecpgQuery = NULL;
    }
 
    return entNo;