From a527e8cc7324bc3e62dfa50ea30d33b2afc01022 Mon Sep 17 00:00:00 2001
From: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Date: Mon, 20 Aug 2018 22:11:41 +0530
Subject: [PATCH] cap-v4l: remove unwanted loop in V4L2 mainloop

The while loop would run only once making it useless and leading
to confusion.

So, remove the unwanted while loop and just keep an infinite for
loop.
---
 modules/videoio/src/cap_v4l.cpp | 56 +++++++++++++++------------------
 1 file changed, 25 insertions(+), 31 deletions(-)

diff --git a/modules/videoio/src/cap_v4l.cpp b/modules/videoio/src/cap_v4l.cpp
index e5c37281aa..0416231f65 100644
--- a/modules/videoio/src/cap_v4l.cpp
+++ b/modules/videoio/src/cap_v4l.cpp
@@ -857,45 +857,39 @@ static int read_frame_v4l2(CvCaptureCAM_V4L* capture) {
 }
 
 static int mainloop_v4l2(CvCaptureCAM_V4L* capture) {
-    unsigned int count;
+    for (;;) {
+        fd_set fds;
+        struct timeval tv;
+        int r;
 
-    count = 1;
+        FD_ZERO (&fds);
+        FD_SET (capture->deviceHandle, &fds);
 
-    while (count-- > 0) {
-        for (;;) {
-            fd_set fds;
-            struct timeval tv;
-            int r;
+        /* Timeout. */
+        tv.tv_sec = 10;
+        tv.tv_usec = 0;
 
-            FD_ZERO (&fds);
-            FD_SET (capture->deviceHandle, &fds);
+        r = select (capture->deviceHandle+1, &fds, NULL, NULL, &tv);
 
-            /* Timeout. */
-            tv.tv_sec = 10;
-            tv.tv_usec = 0;
+        if (-1 == r) {
+            if (EINTR == errno)
+                continue;
 
-            r = select (capture->deviceHandle+1, &fds, NULL, NULL, &tv);
-
-            if (-1 == r) {
-                if (EINTR == errno)
-                    continue;
-
-                perror ("select");
-            }
+            perror ("select");
+        }
 
-            if (0 == r) {
-                fprintf (stderr, "select timeout\n");
+        if (0 == r) {
+            fprintf (stderr, "select timeout\n");
 
-                /* end the infinite loop */
-                break;
-            }
-
-            int returnCode = read_frame_v4l2 (capture);
-            if(returnCode == -1)
-                return -1;
-            if(returnCode == 1)
-                return 1;
+            /* end the infinite loop */
+            break;
         }
+
+        int returnCode = read_frame_v4l2 (capture);
+        if(returnCode == -1)
+            return -1;
+        if(returnCode == 1)
+            return 1;
     }
     return 0;
 }