libbb/progress.c: make sure we never get negative ETA

function                                             old     new   delta
bb_progress_update                                   738     733      -5

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

diff --git a/libbb/progress.c b/libbb/progress.c
index 3999e0f38e73bee8288c2f41cb5873b718463e02..1062e9a0d02e163e0b53c90b2b6cc6a85f77607d 100644 (file)
--- a/libbb/progress.c
+++ b/libbb/progress.c
@@ -79,16 +79,20 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
        int barlength;
        int kiloscale;
 
-       beg_and_transferred = beg_size + transferred;
-
        elapsed = monotonic_sec();
        since_last_update = elapsed - p->lastupdate_sec;
-       /*
-        * Do not update on every call
-        * (we can be called on every network read!)
-        */
-       if (since_last_update == 0 && beg_and_transferred < totalsize)
+
+       if (totalsize != 0 && transferred >= totalsize - beg_size) {
+               /* Last call. Do not skip this update */
+               transferred = totalsize - beg_size; /* sanitize just in case */
+       }
+       else if (since_last_update == 0) {
+               /*
+                * Do not update on every call
+                * (we can be called on every network read!)
+                */
                return;
+       }
 
        kiloscale = 0;
        /*
@@ -101,32 +105,29 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
                /*
                 * 64-bit CPU || small off_t: in either case,
                 * >> is cheap, single-word operation.
-                * ... || strange off_t: also use this code (it is safe,
-                * even if suboptimal), because 32/64 optimized one
-                * works only for 64-bit off_t.
+                * ... || strange off_t: also use this code
+                * (it is safe, just suboptimal wrt code size),
+                * because 32/64 optimized one works only for 64-bit off_t.
                 */
                if (totalsize >= (1 << 22)) {
                        totalsize >>= 10;
                        beg_size >>= 10;
                        transferred >>= 10;
-                       beg_and_transferred >>= 10;
                        kiloscale = 1;
                }
        } else {
                /* 32-bit CPU and 64-bit off_t.
-                * Pick a shift (40 bits) which is easier to do on 32-bit CPU.
+                * Use a 40-bit shift, it is easier to do on 32-bit CPU.
                 */
                if (totalsize >= (uoff_t)(1ULL << 54)) {
                        totalsize = (uint32_t)(totalsize >> 32) >> 8;
                        beg_size = (uint32_t)(beg_size >> 32) >> 8;
                        transferred = (uint32_t)(transferred >> 32) >> 8;
-                       beg_and_transferred = (uint32_t)(beg_and_transferred >> 32) >> 8;
                        kiloscale = 4;
                }
        }
 
-       if (beg_and_transferred > totalsize)
-               beg_and_transferred = totalsize;
+       beg_and_transferred = beg_size + transferred;
 
        ratio = 100 * beg_and_transferred / totalsize;
 #if ENABLE_UNICODE_SUPPORT
@@ -163,7 +164,7 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
                p->lastupdate_sec = elapsed;
                p->lastsize = transferred;
                if (since_last_update >= STALLTIME) {
-                       /* We "cut off" these seconds from elapsed time
+                       /* We "cut out" these seconds from elapsed time
                         * by adjusting start time */
                        p->start_sec += since_last_update;
                }