DefineCollation() code cleanup

Reorganize the code in DefineCollation() so that the parts using the
FROM clause and the parts not doing so are more cleanly separated.  No
functionality change intended.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/29ae752f-80e9-8d31-601c-62cf01cc93d8@enterprisedb.com

diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 12fc2316f974c51b43e5c044085a477367bce291..93df1d366c6e3393483aea4e3cd7506a02b88e4e 100644 (file)
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -63,12 +63,11 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
        DefElem    *providerEl = NULL;
        DefElem    *deterministicEl = NULL;
        DefElem    *versionEl = NULL;
-       char       *collcollate = NULL;
-       char       *collctype = NULL;
-       char       *collproviderstr = NULL;
-       bool            collisdeterministic = true;
-       int                     collencoding = 0;
-       char            collprovider = 0;
+       char       *collcollate;
+       char       *collctype;
+       bool            collisdeterministic;
+       int                     collencoding;
+       char            collprovider;
        char       *collversion = NULL;
        Oid                     newoid;
        ObjectAddress address;
@@ -167,65 +166,71 @@ DefineCollation(ParseState *pstate, List *names, List *parameters, bool if_not_e
                                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                                         errmsg("collation \"default\" cannot be copied")));
        }
-
-       if (localeEl)
+       else
        {
-               collcollate = defGetString(localeEl);
-               collctype = defGetString(localeEl);
-       }
+               char       *collproviderstr = NULL;
 
-       if (lccollateEl)
-               collcollate = defGetString(lccollateEl);
+               collcollate = NULL;
+               collctype = NULL;
 
-       if (lcctypeEl)
-               collctype = defGetString(lcctypeEl);
+               if (localeEl)
+               {
+                       collcollate = defGetString(localeEl);
+                       collctype = defGetString(localeEl);
+               }
 
-       if (providerEl)
-               collproviderstr = defGetString(providerEl);
+               if (lccollateEl)
+                       collcollate = defGetString(lccollateEl);
 
-       if (deterministicEl)
-               collisdeterministic = defGetBoolean(deterministicEl);
+               if (lcctypeEl)
+                       collctype = defGetString(lcctypeEl);
 
-       if (versionEl)
-               collversion = defGetString(versionEl);
+               if (providerEl)
+                       collproviderstr = defGetString(providerEl);
 
-       if (collproviderstr)
-       {
-               if (pg_strcasecmp(collproviderstr, "icu") == 0)
-                       collprovider = COLLPROVIDER_ICU;
-               else if (pg_strcasecmp(collproviderstr, "libc") == 0)
-                       collprovider = COLLPROVIDER_LIBC;
+               if (deterministicEl)
+                       collisdeterministic = defGetBoolean(deterministicEl);
+               else
+                       collisdeterministic = true;
+
+               if (versionEl)
+                       collversion = defGetString(versionEl);
+
+               if (collproviderstr)
+               {
+                       if (pg_strcasecmp(collproviderstr, "icu") == 0)
+                               collprovider = COLLPROVIDER_ICU;
+                       else if (pg_strcasecmp(collproviderstr, "libc") == 0)
+                               collprovider = COLLPROVIDER_LIBC;
+                       else
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+                                                errmsg("unrecognized collation provider: %s",
+                                                               collproviderstr)));
+               }
                else
+                       collprovider = COLLPROVIDER_LIBC;
+
+               if (!collcollate)
                        ereport(ERROR,
                                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                        errmsg("unrecognized collation provider: %s",
-                                                       collproviderstr)));
-       }
-       else if (!fromEl)
-               collprovider = COLLPROVIDER_LIBC;
-
-       if (!collcollate)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                errmsg("parameter \"lc_collate\" must be specified")));
+                                        errmsg("parameter \"lc_collate\" must be specified")));
 
-       if (!collctype)
-               ereport(ERROR,
-                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                errmsg("parameter \"lc_ctype\" must be specified")));
+               if (!collctype)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+                                        errmsg("parameter \"lc_ctype\" must be specified")));
 
-       /*
-        * Nondeterministic collations are currently only supported with ICU
-        * because that's the only case where it can actually make a difference.
-        * So we can save writing the code for the other providers.
-        */
-       if (!collisdeterministic && collprovider != COLLPROVIDER_ICU)
-               ereport(ERROR,
-                               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-                                errmsg("nondeterministic collations not supported with this provider")));
+               /*
+                * Nondeterministic collations are currently only supported with ICU
+                * because that's the only case where it can actually make a difference.
+                * So we can save writing the code for the other providers.
+                */
+               if (!collisdeterministic && collprovider != COLLPROVIDER_ICU)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                                        errmsg("nondeterministic collations not supported with this provider")));
 
-       if (!fromEl)
-       {
                if (collprovider == COLLPROVIDER_ICU)
                {
 #ifdef USE_ICU