Re-allow custom GUC names that have more than two components.

Commit 3db826bd5 disallowed this case, but it turns out that some
people are depending on it.  Since the core grammar has allowed
it since 3dc37cd8d, it seems like this code should fall in line.

Per bug #17045 from Robert Sosinski.

Discussion: https://postgr.es/m/17045-6a4a9f0d1513f72b@postgresql.org

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 87bc68870469c83b520f0a0448a4e8330ee6a986..68b62d523dc953d0e09239ded994595aee8ab8f6 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -5368,13 +5368,14 @@ add_guc_variable(struct config_generic *var, int elevel)
 /*
  * Decide whether a proposed custom variable name is allowed.
  *
- * It must be "identifier.identifier", where the rules for what is an
- * identifier agree with scan.l.
+ * It must be two or more identifiers separated by dots, where the rules
+ * for what is an identifier agree with scan.l.  (If you change this rule,
+ * adjust the errdetail in find_option().)
  */
 static bool
 valid_custom_variable_name(const char *name)
 {
-   int         num_sep = 0;
+   bool        saw_sep = false;
    bool        name_start = true;
 
    for (const char *p = name; *p; p++)
@@ -5383,7 +5384,7 @@ valid_custom_variable_name(const char *name)
        {
            if (name_start)
                return false;   /* empty name component */
-           num_sep++;
+           saw_sep = true;
            name_start = true;
        }
        else if (strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@@ -5400,8 +5401,8 @@ valid_custom_variable_name(const char *name)
    }
    if (name_start)
        return false;           /* empty name component */
-   /* OK if we had exactly one separator */
-   return (num_sep == 1);
+   /* OK if we found at least one separator */
+   return saw_sep;
 }
 
 /*
@@ -5516,7 +5517,7 @@ find_option(const char *name, bool create_placeholders, bool skip_errors,
                        (errcode(ERRCODE_INVALID_NAME),
                         errmsg("invalid configuration parameter name \"%s\"",
                                name),
-                        errdetail("Custom parameter names must be of the form \"identifier.identifier\".")));
+                        errdetail("Custom parameter names must be two or more simple identifiers separated by dots.")));
            return NULL;
        }
    }

diff --git a/src/test/regress/expected/guc.out b/src/test/regress/expected/guc.out
index c55871a972e0b13c9bfc80eb8b4f2fc48721d18b..59da91ff04de6854dbc549e2d6b76ab0ac79f4c7 100644 (file)
--- a/src/test/regress/expected/guc.out
+++ b/src/test/regress/expected/guc.out
@@ -515,6 +515,8 @@ SET no_such_variable TO 42;
 ERROR:  unrecognized configuration parameter "no_such_variable"
 -- Test "custom" GUCs created on the fly (which aren't really an
 -- intended feature, but many people use them).
+SHOW custom.my_guc;  -- error, not known yet
+ERROR:  unrecognized configuration parameter "custom.my_guc"
 SET custom.my_guc = 42;
 SHOW custom.my_guc;
  custom.my_guc 
@@ -522,14 +524,28 @@ SHOW custom.my_guc;
  42
 (1 row)
 
+RESET custom.my_guc;  -- this makes it go to empty, not become unknown again
+SHOW custom.my_guc;
+ custom.my_guc 
+---------------
+ 
+(1 row)
+
+SET custom.my.qualified.guc = 'foo';
+SHOW custom.my.qualified.guc;
+ custom.my.qualified.guc 
+-------------------------
+ foo
+(1 row)
+
 SET custom."bad-guc" = 42;  -- disallowed because -c cannot set this name
 ERROR:  invalid configuration parameter name "custom.bad-guc"
-DETAIL:  Custom parameter names must be of the form "identifier.identifier".
+DETAIL:  Custom parameter names must be two or more simple identifiers separated by dots.
 SHOW custom."bad-guc";
 ERROR:  unrecognized configuration parameter "custom.bad-guc"
 SET special."weird name" = 'foo';  -- could be allowed, but we choose not to
 ERROR:  invalid configuration parameter name "special.weird name"
-DETAIL:  Custom parameter names must be of the form "identifier.identifier".
+DETAIL:  Custom parameter names must be two or more simple identifiers separated by dots.
 SHOW special."weird name";
 ERROR:  unrecognized configuration parameter "special.weird name"
 --

diff --git a/src/test/regress/sql/guc.sql b/src/test/regress/sql/guc.sql
index 3650188d9d767aae6e81384090289df26417a476..c39c11388d51f9d54952107bfe1b44aa9a7bc378 100644 (file)
--- a/src/test/regress/sql/guc.sql
+++ b/src/test/regress/sql/guc.sql
@@ -151,8 +151,13 @@ SET no_such_variable TO 42;
 
 -- Test "custom" GUCs created on the fly (which aren't really an
 -- intended feature, but many people use them).
+SHOW custom.my_guc;  -- error, not known yet
 SET custom.my_guc = 42;
 SHOW custom.my_guc;
+RESET custom.my_guc;  -- this makes it go to empty, not become unknown again
+SHOW custom.my_guc;
+SET custom.my.qualified.guc = 'foo';
+SHOW custom.my.qualified.guc;
 SET custom."bad-guc" = 42;  -- disallowed because -c cannot set this name
 SHOW custom."bad-guc";
 SET special."weird name" = 'foo';  -- could be allowed, but we choose not to