Formatted output functions (mpfr_*printf): bug fix; added tests.

  * src/vasprintf.c: in buffer_cat, replaced incorrect assertion len > 0
    by a test.
    Note that len == 0 is possible when outputting an integer 0
    (either a native one or mpfr_prec_t) with precision field = 0.
    The consequence of this bug:
      - In debug mode (MPFR_ASSERTD assertion checking), one would get
        an assertion failure.
      - Otherwise, there should be no side effects since the code was
        valid for len == 0, possibly except with LTO (very unlikely,
        though).
    This incorrect assertion was added on 2009-03-13 in r6099.
  * tests/tsprintf.c: added tests of native integer 0 and mpfr_prec_t
    (specifier 'P') with precision field 0, both yielding a call to
    buffer_cat with len = 0.

(merged changesets r14514,14520-14521 from the trunk)

git-svn-id: https://scm.gforge.inria.fr/anonscm/svn/mpfr/branches/4.1@14524 280ebfd0-de03-0410-8827-d642c229c3f4

2 files changed, 21 insertions, 4 deletions

diff --git a/src/vasprintf.c b/src/vasprintf.c
index fca6804d4..d33f478ef 100644
--- a/src/vasprintf.c
+++ b/src/vasprintf.c
@@ -635,7 +635,13 @@ buffer_widen (struct string_buffer *b, size_t len)
 static int
 buffer_cat (struct string_buffer *b, const char *s, size_t len)
 {
-  MPFR_ASSERTD (len > 0);
+  /* If len == 0, which is possible when outputting an integer 0
+     (either a native one or mpfr_prec_t) with precision field = 0,
+     do nothing. This test is not necessary since the code below is
+     valid for len == 0, but this is safer, just in case. */
+  if (len == 0)
+    return 0;
+
   MPFR_ASSERTD (len <= strlen (s));
 
   if (buffer_incr_len (b, len))
diff --git a/tests/tsprintf.c b/tests/tsprintf.c
index 20e83ad0b..9cd25e1ef 100644
--- a/tests/tsprintf.c
+++ b/tests/tsprintf.c
@@ -193,6 +193,10 @@ native_types (void)
   sprintf (buf, "%d", i);
   check_vsprintf (buf, "%d", i);
 
+  check_vsprintf ("0", "%d", 0);
+  check_vsprintf ("", "%.d", 0);
+  check_vsprintf ("", "%.0d", 0);
+
   sprintf (buf, "%e", d);
   check_vsprintf (buf, "%e", d);
 
@@ -227,9 +231,6 @@ decimal (void)
   mpfr_prec_t p = 128;
   mpfr_t x, y, z;
 
-  mpfr_init (z);
-  mpfr_init2 (x, p);
-
   /* specifier 'P' for precision */
   check_vsprintf ("128", "%Pu", p);
   check_vsprintf ("00128", "%.5Pu", p);
@@ -247,9 +248,19 @@ decimal (void)
   check_vsprintf ("0200:", "%0#+ -Po:", p);
   check_vsprintf ("+0000128 :", "%0+ *.*Pd:", -9, 7, p);
   check_vsprintf ("+12345   :", "%0+ -*.*Pd:", -9, -3, (mpfr_prec_t) 12345);
+  check_vsprintf ("0", "%Pu", (mpfr_prec_t) 0);
   /* Do not add a test like "%05.1Pd" as MS Windows is buggy: when
      a precision is given, the '0' flag must be ignored. */
 
+  /* specifier 'P' with precision field 0 */
+  check_vsprintf ("128", "%.Pu", p);
+  check_vsprintf ("128", "%.0Pd", p);
+  check_vsprintf ("", "%.Pu", (mpfr_prec_t) 0);
+  check_vsprintf ("", "%.0Pd", (mpfr_prec_t) 0);
+
+  mpfr_init (z);
+  mpfr_init2 (x, 128);
+
   /* special numbers */
   mpfr_set_inf (x, 1);
   check_sprintf (pinf_str, "%Re", x);