From 86197a14f4c8e932d98785e90b142b5be25eaf2a Mon Sep 17 00:00:00 2001
From: Jochen Topf <jochen@topf.org>
Date: Thu, 26 Jan 2017 21:00:25 +0100
Subject: [PATCH] Bugfix: Terminate called on full buffer.

A full non-auto-growing buffer could lead to the program terminating
instead of a thrown exception. Reason was that the number of bytes
written to the buffer was not tracked properly when appending tag keys
and values to the buffer. The destructor on the TagListBuilder would
then throw another exception which terminates the program. This should
fix this problem by keeping the number of bytes written to the buffer
correctly.

See #189.
---
 include/osmium/builder/builder.hpp            | 18 ++++++++++++++++-
 include/osmium/builder/osm_object_builder.hpp | 20 ++++++++++---------
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/include/osmium/builder/builder.hpp b/include/osmium/builder/builder.hpp
index 107f4a9d0..d4358843b 100644
--- a/include/osmium/builder/builder.hpp
+++ b/include/osmium/builder/builder.hpp
@@ -167,6 +167,20 @@ namespace osmium {
                 return length;
             }
 
+            /**
+             * Append data to buffer and append an additional \0.
+             *
+             * @param data Pointer to data.
+             * @param length Length of data in bytes.
+             * @returns The number of bytes appended (length + 1).
+             */
+            osmium::memory::item_size_type append_with_zero(const char* data, const osmium::memory::item_size_type length) {
+                unsigned char* target = reserve_space(length + 1);
+                std::copy_n(reinterpret_cast<const unsigned char*>(data), length, target);
+                target[length] = '\0';
+                return length + 1;
+            }
+
             /**
              * Append \0-terminated string to buffer.
              *
@@ -180,9 +194,11 @@ namespace osmium {
             /**
              * Append '\0' to the buffer.
              *
+             * @deprecated Use append_with_zero() instead.
+             *
              * @returns The number of bytes appended (always 1).
              */
-            osmium::memory::item_size_type append_zero() {
+            OSMIUM_DEPRECATED osmium::memory::item_size_type append_zero() {
                 *reserve_space(1) = '\0';
                 return 1;
             }
diff --git a/include/osmium/builder/osm_object_builder.hpp b/include/osmium/builder/osm_object_builder.hpp
index 1dd5f972f..d4483b192 100644
--- a/include/osmium/builder/osm_object_builder.hpp
+++ b/include/osmium/builder/osm_object_builder.hpp
@@ -99,7 +99,8 @@ namespace osmium {
                 if (std::strlen(value) > osmium::max_osm_string_length) {
                     throw std::length_error("OSM tag value is too long");
                 }
-                add_size(append(key) + append(value));
+                add_size(append(key));
+                add_size(append(value));
             }
 
             /**
@@ -117,8 +118,8 @@ namespace osmium {
                 if (value_length > osmium::max_osm_string_length) {
                     throw std::length_error("OSM tag value is too long");
                 }
-                add_size(append(key,   osmium::memory::item_size_type(key_length))   + append_zero() +
-                         append(value, osmium::memory::item_size_type(value_length)) + append_zero());
+                add_size(append_with_zero(key,   osmium::memory::item_size_type(key_length)));
+                add_size(append_with_zero(value, osmium::memory::item_size_type(value_length)));
             }
 
             /**
@@ -134,8 +135,8 @@ namespace osmium {
                 if (value.size() > osmium::max_osm_string_length) {
                     throw std::length_error("OSM tag value is too long");
                 }
-                add_size(append(key.data(),   osmium::memory::item_size_type(key.size())   + 1) +
-                         append(value.data(), osmium::memory::item_size_type(value.size()) + 1));
+                add_size(append(key.data(),   osmium::memory::item_size_type(key.size())   + 1));
+                add_size(append(value.data(), osmium::memory::item_size_type(value.size()) + 1));
             }
 
             /**
@@ -144,7 +145,8 @@ namespace osmium {
              * @param tag Tag.
              */
             void add_tag(const osmium::Tag& tag) {
-                add_size(append(tag.key()) + append(tag.value()));
+                add_size(append(tag.key()));
+                add_size(append(tag.value()));
             }
 
             /**
@@ -226,7 +228,7 @@ namespace osmium {
                     throw std::length_error("OSM relation member role is too long");
                 }
                 member.set_role_size(osmium::string_size_type(length) + 1);
-                add_size(append(role, osmium::memory::item_size_type(length)) + append_zero());
+                add_size(append_with_zero(role, osmium::memory::item_size_type(length)));
                 add_padding(true);
             }
 
@@ -310,7 +312,7 @@ namespace osmium {
                     throw std::length_error("OSM user name is too long");
                 }
                 comment.set_user_size(osmium::string_size_type(length) + 1);
-                add_size(append(user, osmium::memory::item_size_type(length)) + append_zero());
+                add_size(append_with_zero(user, osmium::memory::item_size_type(length)));
             }
 
             void add_text(osmium::ChangesetComment& comment, const char* text, const size_t length) {
@@ -322,7 +324,7 @@ namespace osmium {
                     throw std::length_error("OSM changeset comment is too long");
                 }
                 comment.set_text_size(osmium::string_size_type(length) + 1);
-                add_size(append(text, osmium::memory::item_size_type(length)) + append_zero());
+                add_size(append_with_zero(text, osmium::memory::item_size_type(length)));
                 add_padding(true);
             }