Index: Zend/zend_compile.c
===================================================================
RCS file: /repository/ZendEngine2/zend_compile.c,v
retrieving revision 1.647.2.27.2.41.2.31
diff -u -r1.647.2.27.2.41.2.31 zend_compile.c
--- Zend/zend_compile.c	13 Dec 2007 10:02:03 -0000	1.647.2.27.2.41.2.31
+++ Zend/zend_compile.c	22 Dec 2007 06:40:09 -0000
@@ -1191,6 +1191,14 @@
 		efree(lcname);
 	} else {
 		zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);
+		int alias_clash = 0;
+		zval **alias;
+
+		/* Function name must not conflict with import names */
+		if (CG(current_import) &&
+		    zend_hash_find(CG(current_import), lcname, Z_STRLEN(function_name->u.constant)+1, (void**)&alias) == SUCCESS) {
+			alias_clash = 1;
+		}
 
 		if (CG(current_namespace)) {
 			/* Prefix function name with current namespcae name */
@@ -1199,12 +1207,24 @@
 			tmp.u.constant = *CG(current_namespace);
 			zval_copy_ctor(&tmp.u.constant);
 			zend_do_build_namespace_name(&tmp, &tmp, function_name TSRMLS_CC);
+			function_name = &tmp;
 			op_array.function_name = Z_STRVAL(tmp.u.constant);
 			efree(lcname);
 			name_len = Z_STRLEN(tmp.u.constant);
 			lcname = zend_str_tolower_dup(Z_STRVAL(tmp.u.constant), name_len);
 		}
 
+		if (alias_clash) {
+			/* Check if clashing alias actually points to a different name */
+			char *tmp = zend_str_tolower_dup(Z_STRVAL_PP(alias), Z_STRLEN_PP(alias));
+
+			if (Z_STRLEN_PP(alias) != Z_STRLEN(function_name->u.constant) ||
+				memcmp(tmp, lcname, Z_STRLEN(function_name->u.constant))) {
+				zend_error(E_COMPILE_ERROR, "Cannot declare function %s because the name is already in use", Z_STRVAL(function_name->u.constant));
+			}
+			efree(tmp);
+		}
+
 		opline->opcode = ZEND_DECLARE_FUNCTION;
 		opline->op1.op_type = IS_CONST;
 		build_runtime_defined_function_key(&opline->op1.u.constant, lcname, name_len TSRMLS_CC);
@@ -1380,23 +1400,34 @@
 	char *lcname;
 	int prefix_len = 0;
 
-	if (check_namespace && CG(current_namespace)) {
-		/* We assume we call function from the current namespace
-		   if it is not prefixed. */
-		znode tmp;
+	lcname = zend_str_tolower_dup(function_name->u.constant.value.str.val, function_name->u.constant.value.str.len);
 
-		tmp.op_type = IS_CONST;
-		tmp.u.constant = *CG(current_namespace);
-		zval_copy_ctor(&tmp.u.constant);
-		zend_do_build_namespace_name(&tmp, &tmp, function_name TSRMLS_CC);
-		*function_name = tmp;
+	if (check_namespace && (CG(current_import) || CG(current_namespace))) {
+		zval **alias;
 
-		/* In run-time PHP will check for function with full name and
-		   internal function with short name */
-		prefix_len = Z_STRLEN_P(CG(current_namespace)) + 2;
+		if (CG(current_import) &&
+		    zend_hash_find(CG(current_import), lcname, Z_STRLEN(function_name->u.constant)+1, (void**)&alias) == SUCCESS) {
+		    /* The given name is an import name. Substitute it. */
+			zval_dtor(&function_name->u.constant);
+			function_name->u.constant = **alias;
+			zval_copy_ctor(&function_name->u.constant);
+		} else if (CG(current_namespace)) {
+			/* We assume we call function from the current namespace
+			   if it is not prefixed and is not an import name. */
+			znode tmp;
+
+			tmp.op_type = IS_CONST;
+			tmp.u.constant = *CG(current_namespace);
+			zval_copy_ctor(&tmp.u.constant);
+			zend_do_build_namespace_name(&tmp, &tmp, function_name TSRMLS_CC);
+			*function_name = tmp;
+
+			/* In run-time PHP will check for function with full name and
+			   internal function with short name */
+			prefix_len = Z_STRLEN_P(CG(current_namespace)) + 2;
+		}
 	}
 	
-	lcname = zend_str_tolower_dup(function_name->u.constant.value.str.val, function_name->u.constant.value.str.len);
 	if (zend_hash_find(CG(function_table), lcname, function_name->u.constant.value.str.len+1, (void **) &function)==FAILURE) {
 		zend_do_begin_dynamic_function_call(function_name, prefix_len TSRMLS_CC);
 		efree(lcname);
@@ -4825,7 +4856,8 @@
 		ns_name[Z_STRLEN_P(CG(current_namespace))] = ':';
 		ns_name[Z_STRLEN_P(CG(current_namespace))+1] = ':';
 		memcpy(ns_name+Z_STRLEN_P(CG(current_namespace))+2, lcname, Z_STRLEN_P(name)+1);
-		if (zend_hash_exists(CG(class_table), ns_name, Z_STRLEN_P(CG(current_namespace)) + 2 + Z_STRLEN_P(name)+1)) {
+		if (zend_hash_exists(CG(class_table), ns_name, Z_STRLEN_P(CG(current_namespace)) + 2 + Z_STRLEN_P(name)+1) ||
+		    zend_hash_exists(CG(function_table), ns_name, Z_STRLEN_P(CG(current_namespace)) + 2 + Z_STRLEN_P(name)+1)) {
 			char *tmp = zend_str_tolower_dup(Z_STRVAL_P(ns), Z_STRLEN_P(ns));
 
 			if (Z_STRLEN_P(ns) != Z_STRLEN_P(CG(current_namespace)) + 2 + Z_STRLEN_P(name) ||
@@ -4835,7 +4867,8 @@
 			efree(tmp);
 		}
 		efree(ns_name);
-	} else if (zend_hash_exists(CG(class_table), lcname, Z_STRLEN_P(name)+1)) {
+	} else if (zend_hash_exists(CG(class_table), lcname, Z_STRLEN_P(name)+1) ||
+	           zend_hash_exists(CG(function_table), lcname, Z_STRLEN_P(name)+1)) {
 		char *tmp = zend_str_tolower_dup(Z_STRVAL_P(ns), Z_STRLEN_P(ns));
 
 		if (Z_STRLEN_P(ns) != Z_STRLEN_P(name) ||