diff options
Diffstat (limited to 'src/buffer.c')
| -rw-r--r-- | src/buffer.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/src/buffer.c b/src/buffer.c index 27e20d562..def3496ce 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -328,6 +328,10 @@ int git_buf_join( size_t strlen_a = strlen(str_a); size_t strlen_b = strlen(str_b); int need_sep = 0; + ssize_t offset_a = -1; + + /* not safe to have str_b point internally to the buffer */ + assert(str_b < buf->ptr || str_b > buf->ptr + buf->size); /* figure out if we need to insert a separator */ if (separator && strlen_a) { @@ -336,14 +340,24 @@ int git_buf_join( need_sep = 1; } + /* str_a could be part of the buffer */ + if (str_a >= buf->ptr && str_a < buf->ptr + buf->size) + offset_a = str_a - buf->ptr; + error = git_buf_grow(buf, strlen_a + strlen_b + need_sep + 1); if (error < GIT_SUCCESS) return error; - memmove(buf->ptr, str_a, strlen_a); + /* fix up internal pointers */ + if (offset_a >= 0) + str_a = buf->ptr + offset_a; + + /* do the actual copying */ + if (offset_a != 0) + memmove(buf->ptr, str_a, strlen_a); if (need_sep) buf->ptr[strlen_a] = separator; - memmove(buf->ptr + strlen_a + need_sep, str_b, strlen_b); + memcpy(buf->ptr + strlen_a + need_sep, str_b, strlen_b); buf->size = strlen_a + strlen_b + need_sep; buf->ptr[buf->size] = '\0'; |