a potential bug of NPD

Hi, I found a potential null pointer dereference bug in the project source code of libshout, and I have shown the execution sequence of the program that may generate the bug on the graph below. The red text illustrates the steps that generate the bug,the file path can be seen in the blue framed section.

what i am confused about is, there are some code snippets can be found in project that checking if return value of httpp_getvar equal to null, maybe the context in which the code snippet is located can asserts that the return value cannot be equal to null? but I haven't found such code can assert this.

Although the code shown is for the latest but is still exist in current version.would you help to check if this bug is true?thank you for your patience and effort!