libavcodec/utils.c:398: error: Null Dereference
  pointer `buf` last assigned on line 388 could be null and is dereferenced at line 398, column 5.

libavcodec/utils.c:380:1: start of procedure avcodec_default_release_buffer()
378. }
379. 
380. void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
     ^
381.     int i;
382.     InternalBuffer *buf, *last;

libavcodec/utils.c:384:5: 
382.     InternalBuffer *buf, *last;
383. 
384.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
         ^
385.     assert(s->internal_buffer_count);
386. 

libavcodec/utils.c:385:5: 
383. 
384.     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
385.     assert(s->internal_buffer_count);
         ^
386. 
387.     if(s->internal_buffer){

libavcodec/utils.c:387:8: Taking true branch
385.     assert(s->internal_buffer_count);
386. 
387.     if(s->internal_buffer){
            ^
388.     buf = NULL; /* avoids warning */
389.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize

libavcodec/utils.c:388:5: 
386. 
387.     if(s->internal_buffer){
388.     buf = NULL; /* avoids warning */
         ^
389.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
390.         buf= &((InternalBuffer*)s->internal_buffer)[i];

libavcodec/utils.c:389:9: 
387.     if(s->internal_buffer){
388.     buf = NULL; /* avoids warning */
389.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
             ^
390.         buf= &((InternalBuffer*)s->internal_buffer)[i];
391.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:389:14: Loop condition is false. Leaving loop
387.     if(s->internal_buffer){
388.     buf = NULL; /* avoids warning */
389.     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
                  ^
390.         buf= &((InternalBuffer*)s->internal_buffer)[i];
391.         if(buf->data[0] == pic->data[0])

libavcodec/utils.c:394:5: 
392.             break;
393.     }
394.     assert(i < s->internal_buffer_count);
         ^
395.     s->internal_buffer_count--;
396.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];

libavcodec/utils.c:395:5: 
393.     }
394.     assert(i < s->internal_buffer_count);
395.     s->internal_buffer_count--;
         ^
396.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
397. 

libavcodec/utils.c:396:5: 
394.     assert(i < s->internal_buffer_count);
395.     s->internal_buffer_count--;
396.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
         ^
397. 
398.     FFSWAP(InternalBuffer, *buf, *last);

libavcodec/utils.c:398:5: 
396.     last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
397. 
398.     FFSWAP(InternalBuffer, *buf, *last);
         ^
399.     }
400. 

void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
    int i;
    InternalBuffer *buf, *last;
    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
    assert(s->internal_buffer_count);
    if(s->internal_buffer){
    buf = NULL;
    for(i=0; i<s->internal_buffer_count; i++){
        buf= &((InternalBuffer*)s->internal_buffer)[i];
        if(buf->data[0] == pic->data[0])
            break;
    }
    assert(i < s->internal_buffer_count);
    s->internal_buffer_count--;
    last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];
    FFSWAP(InternalBuffer, *buf, *last);
    }
    for(i=0; i<4; i++){
        pic->data[i]=NULL;
    }
    if(s->debug&FF_DEBUG_BUFFERS)
        av_log(s, AV_LOG_DEBUG, "default_release_buffer called on pic %p, %d buffers used\n", pic, s->internal_buffer_count);
}
['void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){\n    int i;\n    InternalBuffer *buf, *last;\n    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);\n    assert(s->internal_buffer_count);\n    if(s->internal_buffer){\n    buf = NULL;\n    for(i=0; i<s->internal_buffer_count; i++){\n        buf= &((InternalBuffer*)s->internal_buffer)[i];\n        if(buf->data[0] == pic->data[0])\n            break;\n    }\n    assert(i < s->internal_buffer_count);\n    s->internal_buffer_count--;\n    last = &((InternalBuffer*)s->internal_buffer)[s->internal_buffer_count];\n    FFSWAP(InternalBuffer, *buf, *last);\n    }\n    for(i=0; i<4; i++){\n        pic->data[i]=NULL;\n    }\n    if(s->debug&FF_DEBUG_BUFFERS)\n        av_log(s, AV_LOG_DEBUG, "default_release_buffer called on pic %p, %d buffers used\\n", pic, s->internal_buffer_count);\n}']