Reduce nesting by doing more early returns on error.

This almost entirely avoids any else-after-return in toxcore. One case is
left, and that one is more readable this way.

Why no else after return: https://llvm.org/docs/CodingStandards.html#don-t-use-else-after-a-return
Why exemptions exist: https://blog.mozilla.org/nnethercote/2009/08/31/no-else-after-return-considered-harmful/

2 files changed, 39 insertions, 44 deletions

diff --git a/toxav/video.c b/toxav/video.c
index 5145c29c..17969003 100644
--- a/toxav/video.c
+++ b/toxav/video.c
@@ -299,55 +299,52 @@ void vc_iterate(VCSession *vc)
         return;
     }
 
+    pthread_mutex_lock(vc->queue_mutex);
+
     struct RTPMessage *p;
 
-    vpx_codec_err_t rc;
+    if (!rb_read((RingBuffer *)vc->vbuf_raw, (void **)&p)) {
+        LOGGER_TRACE(vc->log, "no Video frame data available");
+        pthread_mutex_unlock(vc->queue_mutex);
+        return;
+    }
 
-    pthread_mutex_lock(vc->queue_mutex);
+    pthread_mutex_unlock(vc->queue_mutex);
+    const struct RTPHeader *const header = &p->header;
 
     uint32_t full_data_len;
 
-    if (rb_read((RingBuffer *)vc->vbuf_raw, (void **)&p)) {
-        pthread_mutex_unlock(vc->queue_mutex);
-        const struct RTPHeader *const header = &p->header;
+    if (header->flags & RTP_LARGE_FRAME) {
+        full_data_len = header->data_length_full;
+        LOGGER_DEBUG(vc->log, "vc_iterate:001:full_data_len=%d", (int)full_data_len);
+    } else {
+        full_data_len = p->len;
+        LOGGER_DEBUG(vc->log, "vc_iterate:002");
+    }
 
-        if (header->flags & RTP_LARGE_FRAME) {
-            full_data_len = header->data_length_full;
-            LOGGER_DEBUG(vc->log, "vc_iterate:001:full_data_len=%d", (int)full_data_len);
-        } else {
-            full_data_len = p->len;
-            LOGGER_DEBUG(vc->log, "vc_iterate:002");
-        }
+    LOGGER_DEBUG(vc->log, "vc_iterate: rb_read p->len=%d p->header.xe=%d", (int)full_data_len, p->header.xe);
+    LOGGER_DEBUG(vc->log, "vc_iterate: rb_read rb size=%d", (int)rb_size((RingBuffer *)vc->vbuf_raw));
+    const vpx_codec_err_t rc = vpx_codec_decode(vc->decoder, p->data, full_data_len, nullptr, MAX_DECODE_TIME_US);
+    free(p);
 
-        LOGGER_DEBUG(vc->log, "vc_iterate: rb_read p->len=%d p->header.xe=%d", (int)full_data_len, p->header.xe);
-        LOGGER_DEBUG(vc->log, "vc_iterate: rb_read rb size=%d", (int)rb_size((RingBuffer *)vc->vbuf_raw));
-        rc = vpx_codec_decode(vc->decoder, p->data, full_data_len, nullptr, MAX_DECODE_TIME_US);
-        free(p);
+    if (rc != VPX_CODEC_OK) {
+        LOGGER_ERROR(vc->log, "Error decoding video: %d %s", (int)rc, vpx_codec_err_to_string(rc));
+        return;
+    }
 
-        if (rc != VPX_CODEC_OK) {
-            LOGGER_ERROR(vc->log, "Error decoding video: %d %s", (int)rc, vpx_codec_err_to_string(rc));
-        } else {
-            /* Play decoded images */
-            vpx_codec_iter_t iter = nullptr;
-            vpx_image_t *dest = nullptr;
-
-            while ((dest = vpx_codec_get_frame(vc->decoder, &iter)) != nullptr) {
-                if (vc->vcb.first) {
-                    vc->vcb.first(vc->av, vc->friend_number, dest->d_w, dest->d_h,
-                                  (const uint8_t *)dest->planes[0], (const uint8_t *)dest->planes[1], (const uint8_t *)dest->planes[2],
-                                  dest->stride[0], dest->stride[1], dest->stride[2], vc->vcb.second);
-                }
-
-                vpx_img_free(dest); // is this needed? none of the VPx examples show that
-            }
+    /* Play decoded images */
+    vpx_codec_iter_t iter = nullptr;
+    vpx_image_t *dest = nullptr;
+
+    while ((dest = vpx_codec_get_frame(vc->decoder, &iter)) != nullptr) {
+        if (vc->vcb.first) {
+            vc->vcb.first(vc->av, vc->friend_number, dest->d_w, dest->d_h,
+                          (const uint8_t *)dest->planes[0], (const uint8_t *)dest->planes[1], (const uint8_t *)dest->planes[2],
+                          dest->stride[0], dest->stride[1], dest->stride[2], vc->vcb.second);
         }
 
-        return;
-    } else {
-        LOGGER_TRACE(vc->log, "no Video frame data available");
+        vpx_img_free(dest); // is this needed? none of the VPx examples show that
     }
-
-    pthread_mutex_unlock(vc->queue_mutex);
 }
 
 int vc_queue_message(void *vcp, struct RTPMessage *msg)
diff --git a/toxcore/group.c b/toxcore/group.c
index 95de1afb..826ea239 100644
--- a/toxcore/group.c
+++ b/toxcore/group.c
@@ -2270,12 +2270,9 @@ static unsigned int lossy_packet_not_received(Group_c *g, int peer_index, uint16
         g->group[peer_index].top_lossy_number = message_number;
         g->group[peer_index].bottom_lossy_number = (message_number - MAX_LOSSY_COUNT) + 1;
         g->group[peer_index].recv_lossy[message_number % MAX_LOSSY_COUNT] = 1;
-
-        return 0;
     } else {  // top_distance < MAX_LOSSY_COUNT
-        unsigned int i;
-
-        for (i = g->group[peer_index].bottom_lossy_number; i != (g->group[peer_index].bottom_lossy_number + top_distance);
+        for (unsigned int i = g->group[peer_index].bottom_lossy_number;
+                i != g->group[peer_index].bottom_lossy_number + top_distance;
                 ++i) {
             g->group[peer_index].recv_lossy[i % MAX_LOSSY_COUNT] = 0;
         }
@@ -2283,9 +2280,10 @@ static unsigned int lossy_packet_not_received(Group_c *g, int peer_index, uint16
         g->group[peer_index].top_lossy_number = message_number;
         g->group[peer_index].bottom_lossy_number = (message_number - MAX_LOSSY_COUNT) + 1;
         g->group[peer_index].recv_lossy[message_number % MAX_LOSSY_COUNT] = 1;
-
-        return 0;
     }
+
+    return 0;
+
 }
 
 static int handle_lossy(void *object, int friendcon_id, const uint8_t *data, uint16_t length, void *userdata)