Avoid useless malloc/free traffic around getFormattedTypeName().

Coverity complained that one caller of getFormattedTypeName() failed
to free the returned string.  Which is true, but rather than fixing
that one, let's get rid of this tedious and error-prone requirement.
Now that getFormattedTypeName() caches its result, strdup'ing that
result and expecting the caller to free it accomplishes little except
to waste cycles.  We do create a leak in the case where getTypes didn't
make a TypeInfo for the type, but that basically shouldn't ever happen.

Back-patch, as commit 6c450a8 was.  This isn't a particularly
interesting bug fix, but the API change seems like a hazard for
future back-patching activity if we don't back-patch it.

Author: tglsfdc

src/bin/pg_dump/pg_dump.c

@@ -262,7 +262,7 @@ static char *convertRegProcReference(const char *proc);
 static char *getFormattedOperatorName(const char *oproid);
 static char *convertTSFunction(Archive *fout, Oid funcOid);
 static Oid	findLastBuiltinOid_V71(Archive *fout);
-static char *getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts);
+static const char *getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts);
 static void getBlobs(Archive *fout);
 static void dumpBlob(Archive *fout, const BlobInfo *binfo);
 static int	dumpBlobs(Archive *fout, const void *arg);
@@ -11121,13 +11121,9 @@ dumpBaseType(Archive *fout, const TypeInfo *tyinfo)
 		appendPQExpBuffer(q, ",\n    SUBSCRIPT = %s", typsubscript);
 
 	if (OidIsValid(tyinfo->typelem))
-	{
-		char	   *elemType;
-
-		elemType = getFormattedTypeName(fout, tyinfo->typelem, zeroIsError);
-		appendPQExpBuffer(q, ",\n    ELEMENT = %s", elemType);
-		free(elemType);
-	}
+		appendPQExpBuffer(q, ",\n    ELEMENT = %s",
+						  getFormattedTypeName(fout, tyinfo->typelem,
+											   zeroIsError));
 
 	if (strcmp(typcategory, "U") != 0)
 	{
@@ -11931,7 +11927,7 @@ format_function_arguments_old(Archive *fout,
 	for (j = 0; j < nallargs; j++)
 	{
 		Oid			typid;
-		char	   *typname;
+		const char *typname;
 		const char *argmode;
 		const char *argname;
 
@@ -11970,7 +11966,6 @@ format_function_arguments_old(Archive *fout,
 						  argname ? fmtId(argname) : "",
 						  argname ? " " : "",
 						  typname);
-		free(typname);
 	}
 	appendPQExpBufferChar(&fn, ')');
 	return fn.data;
@@ -11999,15 +11994,12 @@ format_function_signature(Archive *fout, const FuncInfo *finfo, bool honor_quote
 		appendPQExpBuffer(&fn, "%s(", finfo->dobj.name);
 	for (j = 0; j < finfo->nargs; j++)
 	{
-		char	   *typname;
-
 		if (j > 0)
 			appendPQExpBufferStr(&fn, ", ");
 
-		typname = getFormattedTypeName(fout, finfo->argtypes[j],
-									   zeroIsError);
-		appendPQExpBufferStr(&fn, typname);
-		free(typname);
+		appendPQExpBufferStr(&fn,
+							 getFormattedTypeName(fout, finfo->argtypes[j],
+												  zeroIsError));
 	}
 	appendPQExpBufferChar(&fn, ')');
 	return fn.data;
@@ -12052,7 +12044,6 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
 	char	   *prosupport;
 	char	   *proparallel;
 	char	   *lanname;
-	char	   *rettypename;
 	int			nallargs;
 	char	  **allargtypes = NULL;
 	char	  **argmodes = NULL;
@@ -12342,14 +12333,10 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
 	else if (funcresult)
 		appendPQExpBuffer(q, " RETURNS %s", funcresult);
 	else
-	{
-		rettypename = getFormattedTypeName(fout, finfo->prorettype,
-										   zeroIsError);
 		appendPQExpBuffer(q, " RETURNS %s%s",
 						  (proretset[0] == 't') ? "SETOF " : "",
-						  rettypename);
-		free(rettypename);
-	}
+						  getFormattedTypeName(fout, finfo->prorettype,
+											   zeroIsError));
 
 	appendPQExpBuffer(q, "\n    LANGUAGE %s", fmtId(lanname));
 
@@ -12556,8 +12543,8 @@ dumpCast(Archive *fout, const CastInfo *cast)
 	PQExpBuffer labelq;
 	PQExpBuffer castargs;
 	FuncInfo   *funcInfo = NULL;
-	char	   *sourceType;
-	char	   *targetType;
+	const char *sourceType;
+	const char *targetType;
 
 	/* Skip if not to be dumped */
 	if (!cast->dobj.dump || dopt->dataOnly)
@@ -12643,9 +12630,6 @@ dumpCast(Archive *fout, const CastInfo *cast)
 					NULL, "",
 					cast->dobj.catId, 0, cast->dobj.dumpId);
 
-	free(sourceType);
-	free(targetType);
-
 	destroyPQExpBuffer(defqry);
 	destroyPQExpBuffer(delqry);
 	destroyPQExpBuffer(labelq);
@@ -12666,7 +12650,7 @@ dumpTransform(Archive *fout, const TransformInfo *transform)
 	FuncInfo   *fromsqlFuncInfo = NULL;
 	FuncInfo   *tosqlFuncInfo = NULL;
 	char	   *lanname;
-	char	   *transformType;
+	const char *transformType;
 
 	/* Skip if not to be dumped */
 	if (!transform->dobj.dump || dopt->dataOnly)
@@ -12773,7 +12757,6 @@ dumpTransform(Archive *fout, const TransformInfo *transform)
 					transform->dobj.catId, 0, transform->dobj.dumpId);
 
 	free(lanname);
-	free(transformType);
 	destroyPQExpBuffer(defqry);
 	destroyPQExpBuffer(delqry);
 	destroyPQExpBuffer(labelq);
@@ -14071,17 +14054,11 @@ format_aggregate_signature(const AggInfo *agginfo, Archive *fout, bool honor_quo
 	{
 		appendPQExpBufferChar(&buf, '(');
 		for (j = 0; j < agginfo->aggfn.nargs; j++)
-		{
-			char	   *typname;
-
-			typname = getFormattedTypeName(fout, agginfo->aggfn.argtypes[j],
-										   zeroIsError);
-
 			appendPQExpBuffer(&buf, "%s%s",
 							  (j > 0) ? ", " : "",
-							  typname);
-			free(typname);
-		}
+							  getFormattedTypeName(fout,
+												   agginfo->aggfn.argtypes[j],
+												   zeroIsError));
 		appendPQExpBufferChar(&buf, ')');
 	}
 	return buf.data;
@@ -18754,8 +18731,10 @@ findDumpableDependencies(ArchiveHandle *AH, const DumpableObject *dobj,
  *
  * This does not guarantee to schema-qualify the output, so it should not
  * be used to create the target object name for CREATE or ALTER commands.
+ *
+ * Note that the result is cached and must not be freed by the caller.
  */
-static char *
+static const char *
 getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
 {
 	TypeInfo   *typeInfo;
@@ -18766,15 +18745,15 @@ getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
 	if (oid == 0)
 	{
 		if ((opts & zeroAsStar) != 0)
-			return pg_strdup("*");
+			return "*";
 		else if ((opts & zeroAsNone) != 0)
-			return pg_strdup("NONE");
+			return "NONE";
 	}
 
 	/* see if we have the result cached in the type's TypeInfo record */
 	typeInfo = findTypeByOid(oid);
 	if (typeInfo && typeInfo->ftypname)
-		return pg_strdup(typeInfo->ftypname);
+		return typeInfo->ftypname;
 
 	query = createPQExpBuffer();
 	appendPQExpBuffer(query, "SELECT pg_catalog.format_type('%u'::pg_catalog.oid, NULL)",
@@ -18788,9 +18767,14 @@ getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts)
 	PQclear(res);
 	destroyPQExpBuffer(query);
 
-	/* cache a copy for later requests */
+	/*
+	 * Cache the result for re-use in later requests, if possible.  If we
+	 * don't have a TypeInfo for the type, the string will be leaked once the
+	 * caller is done with it ... but that case really should not happen, so
+	 * leaking if it does seems acceptable.
+	 */
 	if (typeInfo)
-		typeInfo->ftypname = pg_strdup(result);
+		typeInfo->ftypname = result;
 
 	return result;
 }