tools: mkenvimage: Fix read() stdin error handling

On success read() returns the number of bytes read or zero for EOF. On
error -1 is returned and errno is set, so the right way to test if read
had failed is to test the return value instead of errno.

Signed-off-by: Alexander Dahl <ada@thorsis.com>

diff --git a/tools/mkenvimage.c b/tools/mkenvimage.c
index 8eee72e2572e321bbcf70d516d884708724f7fa4..716cb73a5c63b70d18943e0e9629eb22d9c5965b 100644 (file)
--- a/tools/mkenvimage.c
+++ b/tools/mkenvimage.c
@@ -168,7 +168,7 @@ int main(int argc, char **argv)
                                return EXIT_FAILURE;
                        }
                        readbytes = read(txt_fd, filebuf + filesize, readlen);
-                       if (errno) {
+                       if (readbytes < 0) {
                                fprintf(stderr, "Error while reading stdin: %s\n",
                                                strerror(errno));
                                return EXIT_FAILURE;