Clean up code for widget_in() and widget_out().

Given syntactically wrong input, widget_in() could call atof() with an
indeterminate pointer argument, typically leading to a crash; or if it
didn't do that, it might return a NULL pointer, which again would lead
to a crash since old-style C functions aren't supposed to do things
that way.  Fix that by correcting the off-by-one syntax test and
throwing a proper error rather than just returning NULL.

Also, since widget_in and widget_out have been marked STRICT for a
long time, their tests for null inputs are just dead code; remove 'em.
In the oldest branches, also improve widget_out to use snprintf not
sprintf, just to be sure.

In passing, get rid of a long-since-useless sprintf into a local buffer
that nothing further is done with, and make some other minor coding
style cleanups.

In the intended regression-testing usage of these functions, none of
this is very significant; but if the regression test database were
left around in a production installation, these bugs could amount
to a minor security hazard.

Piotr Stefaniak, Michael Paquier, and Tom Lane

diff --git a/src/test/regress/regress.c b/src/test/regress/regress.c
index be76f7dc416deb30220c876f5e22a06b897cb6f7..697b39aae3a80a822277ce122fcf5b56a3fff314 100644 (file)
--- a/src/test/regress/regress.c
+++ b/src/test/regress/regress.c
@@ -243,25 +243,27 @@ WIDGET *
 widget_in(char *str)
 {
    char       *p,
-              *coord[NARGS],
-               buf2[1000];
+              *coord[NARGS];
    int         i;
    WIDGET     *result;
 
-   if (str == NULL)
-       return NULL;
    for (i = 0, p = str; *p && i < NARGS && *p != RDELIM; p++)
-       if (*p == ',' || (*p == LDELIM && !i))
+   {
+       if (*p == DELIM || (*p == LDELIM && i == 0))
            coord[i++] = p + 1;
-   if (i < NARGS - 1)
-       return NULL;
+   }
+
+   if (i < NARGS)
+       ereport(ERROR,
+               (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+                errmsg("invalid input syntax for type widget: \"%s\"",
+                       str)));
+
    result = (WIDGET *) palloc(sizeof(WIDGET));
    result->center.x = atof(coord[0]);
    result->center.y = atof(coord[1]);
    result->radius = atof(coord[2]);
 
-   snprintf(buf2, sizeof(buf2), "widget_in: read (%f, %f, %f)\n",
-            result->center.x, result->center.y, result->radius);
    return result;
 }
 
@@ -270,12 +272,9 @@ widget_out(WIDGET * widget)
 {
    char       *result;
 
-   if (widget == NULL)
-       return NULL;
-
-   result = (char *) palloc(60);
-   sprintf(result, "(%g,%g,%g)",
-           widget->center.x, widget->center.y, widget->radius);
+   result = (char *) palloc(100);
+   snprintf(result, 100, "(%g,%g,%g)",
+            widget->center.x, widget->center.y, widget->radius);
    return result;
 }