Conversion specification should start with %

nickg · May 23, 2021 · 5d29bec · 5d29bec
1 parent cabd277
commit 5d29bec
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Showing 2 changed files with 10 additions and 6 deletions.
diff --git a/src/rt/rtkern.c b/src/rt/rtkern.c
@@ -1013,10 +1013,14 @@ struct uarray _std_to_string_real_format(double value, struct uarray *format)
    else
       str_len = format->dims[0].left - format->dims[0].right + 1;
 
-   char *LOCAL fmt_str = xmalloc(str_len + 2);
-   fmt_str[0] = '%';
-   memcpy(fmt_str + 1, format->ptr, str_len);
-   fmt_str[str_len + 1] = '\0';
+   char *LOCAL fmt_str = xmalloc(str_len + 1);
+   memcpy(fmt_str, format->ptr, str_len);
+   fmt_str[str_len] = '\0';
+
+   if (fmt_str[0] != '%') {
+      rt_show_trace(NULL);
+      fatal("conversion specification must start with '%%'");
+   }
 
    for (const char *p = fmt_str + 1; *p; p++) {
       switch (*p) {

diff --git a/test/regress/predef1.vhd b/test/regress/predef1.vhd
@@ -51,8 +51,8 @@ begin
         report to_string(r, 0);
         assert to_string(r, 0)(1 to 7) = "1.23456";
 
-        report to_string(r, "1.1f");
-        assert to_string(r, "1.1f") = "1.2";
+        report to_string(r, "%1.1f");
+        assert to_string(r, "%1.1f") = "1.2";
 
         wait;
     end process;