top: tweak 'Inspect' code for isolated edge situations

If the 'Inspect' feature was used to view a file which
contained binary (unprintable) data, and when the last
line for such a file was purely unprintable, then that
line length would be overstated by the terminal width.

This was also the occasion where valgrind might object
over potential reference to some unitialized value(s).
It was a harmless situation and somewhat rare to begin
with. Anyway this commit will eliminate the potential.

Additionally, supporting readfile logic was simplified
and the 'status line' bytes read is now more accurate.

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/top/top.c b/top/top.c
index 07a8f29075b6b5c706f727c574fa997734a879ac..9e88ea50e7fad320828d51f4c239bba430117ecc 100644 (file)
--- a/top/top.c
+++ b/top/top.c
@@ -1223,15 +1223,13 @@ static int readfile (FILE *fp, char **baddr, size_t *bsize, size_t *bread) {
    *bsize = READMINSZ;
    *baddr = alloc_c(READMINSZ);
    if (fp) {
-      while (0 < (num = fread(chunk, 1, sizeof(chunk) -1, fp))) {
-         if (feof(fp) && chunk[num -1]) chunk[num++] = '\0';
+      while (0 < (num = fread(chunk, 1, sizeof(chunk), fp))) {
          *baddr = alloc_r(*baddr, num + *bsize);
          memcpy(*baddr + *bread, chunk, num);
          *bread += num;
          *bsize += num;
       };
-      // adjust for the null terminator, which was counted above
-      if (*bread) --(*bread);
+      *(*baddr + *bread) = '\0';
       return ferror(fp);
    }
    return ENOENT;
@@ -2888,6 +2886,7 @@ static inline void insp_make_row (int col, int row) {
       } else {              mkFND      // a big show (he,he)
          ofs = 0;
       }
+      if (col + fr >= INSP_RLEN(row)) break;
    }
    capNO;
    putp(Cap_clr_eol);