my_vsnprintf() implementation was broken (for old non-C99 compliant OSes)

--HG--
branch : HEAD

diff --git a/src/lib/compat.c b/src/lib/compat.c
index e759741f4abc2b7bc40db81c98ffa673fc965576..c9384e98e811fbf1610beb92ba45c6678a53e131 100644 (file)
--- a/src/lib/compat.c
+++ b/src/lib/compat.c
@@ -258,8 +258,13 @@ int my_vsnprintf(char *str, size_t size, const char *format, va_list ap)
        if (tmp_size > size) {
                tmp = t_buffer_get(tmp_size);
                ret = vsnprintf(tmp, tmp_size, format, ap);
-               if (ret >= 0 && (size_t)ret+1 != size)
+               if (ret >= 0 && (size_t)ret+1 != tmp_size) {
+                       if (size > 0) {
+                               memcpy(str, tmp, size-1);
+                               str[size-1] = '\0';
+                       }
                        return ret;
+               }
        } else {
                tmp_size = size;
        }
@@ -269,9 +274,15 @@ int my_vsnprintf(char *str, size_t size, const char *format, va_list ap)
                tmp_size = nearest_power(tmp_size+1);
                tmp = i_malloc(tmp_size);
                ret = vsnprintf(tmp, tmp_size, format, ap);
-               i_free(tmp);
-               if (ret >= 0 && (size_t)ret+1 != size)
+               if (ret >= 0 && (size_t)ret+1 != tmp_size) {
+                       if (size > 0) {
+                               memcpy(str, tmp, size-1);
+                               str[size-1] = '\0';
+                       }
+                       i_free(tmp);
                        return ret;
+               }
+               i_free(tmp);
        } while (tmp_size < 1024*1024);
 
        i_panic("my_vsnprintf(): Output string too big");