wget: print the final newline only for non-tty output

$ busybox wget URL 2>&1 | cat
Connecting to ....
install.iso          0% |                                | 2629k  0:02:05 ETA
install.iso          7% |**                              | 25.7M  0:00:23 ETA
install.iso         16% |*****                           | 54.1M  0:00:14 ETA
install.iso         20% |******                          | 67.4M  0:00:15 ETA
install.iso         25% |********                        | 81.0M  0:00:14 ETA
install.iso         30% |*********                       | 97.3M  0:00:13 ETA
install.iso         36% |***********                     |  117M  0:00:12 ETA
install.iso         41% |*************                   |  134M  0:00:11 ETA
install.iso         47% |***************                 |  152M  0:00:10 ETA
install.iso         54% |*****************               |  176M  0:00:08 ETA
install.iso         61% |*******************             |  200M  0:00:06 ETA
install.iso         66% |*********************           |  215M  0:00:06 ETA
install.iso         71% |**********************          |  231M  0:00:05 ETA
install.iso         75% |************************        |  244M  0:00:04 ETA
install.iso         79% |*************************       |  257M  0:00:03 ETA
install.iso         84% |***************************     |  275M  0:00:02 ETA
install.iso         91% |*****************************   |  297M  0:00:01 ETA
install.iso         99% |******************************* |  321M  0:00:00 ETA
install.iso        100% |********************************|  323M  0:00:00 ETA
  <-- no empty line here
$

function                                             old     new   delta
bb_progress_update                                   622     632     +10
progress_meter                                       152     158      +6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 16/0)               Total: 16 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 9 insertions, 5 deletions

diff --git a/include/libbb.h b/include/libbb.h
index b041ce047..883457c0d 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -2007,7 +2007,7 @@ typedef struct bb_progress_t {
         (p)->curfile = NULL; \
 } while (0)
 void bb_progress_init(bb_progress_t *p, const char *curfile) FAST_FUNC;
-void bb_progress_update(bb_progress_t *p,
+int bb_progress_update(bb_progress_t *p,
                         uoff_t beg_range,
                         uoff_t transferred,
                         uoff_t totalsize) FAST_FUNC;
diff --git a/libbb/progress.c b/libbb/progress.c
index 23e974ce7..d071ce705 100644
--- a/libbb/progress.c
+++ b/libbb/progress.c
@@ -69,7 +69,7 @@ void FAST_FUNC bb_progress_init(bb_progress_t *p, const char *curfile)
  * will be "totalsize" bytes.
  * If totalsize == 0, then it is unknown.
  */
-void FAST_FUNC bb_progress_update(bb_progress_t *p,
+int FAST_FUNC bb_progress_update(bb_progress_t *p,
                 uoff_t beg_size,
                 uoff_t transferred,
                 uoff_t totalsize)
@@ -94,7 +94,7 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
                  * Do not update on every call
                  * (we can be called on every network read!)
                  */
-                return;
+                return -1;
         }
 
         /* Before we lose real, unscaled sizes, produce human-readable size string */
@@ -211,4 +211,5 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
         }
         if (notty)
                 fputc('\n', stderr);
+        return notty;
 }
diff --git a/networking/wget.c b/networking/wget.c
index 65262e19d..44c481a99 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -283,13 +283,15 @@ enum {
 #if ENABLE_FEATURE_WGET_STATUSBAR
 static void progress_meter(int flag)
 {
+        int notty;
+
         if (option_mask32 & WGET_OPT_QUIET)
                 return;
 
         if (flag == PROGRESS_START)
                 bb_progress_init(&G.pmt, G.curfile);
 
-        bb_progress_update(&G.pmt,
+        notty = bb_progress_update(&G.pmt,
                         G.beg_range,
                         G.transferred,
                         (G.chunked || !G.got_clen) ? 0 : G.beg_range + G.transferred + G.content_len
@@ -297,7 +299,8 @@ static void progress_meter(int flag)
 
         if (flag == PROGRESS_END) {
                 bb_progress_free(&G.pmt);
-                bb_putchar_stderr('\n');
+                if (notty == 0)
+                        bb_putchar_stderr('\n'); /* it's tty */
                 G.transferred = 0;
         }
 }