(Fformat): Limit minlen to avoid stack overflow.

diff --git a/src/editfns.c b/src/editfns.c
index 365d534..37f0e7e 100644 (file)
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -1800,10 +1800,9 @@ Use %% to put a single % into the output.")
 
        /* Process a numeric arg and skip it.  */
        minlen = atoi (format);
-       if (minlen > 0)
-         total += minlen;
-       else
-         total -= minlen;
+       if (minlen < 0)
+         minlen = - minlen;
+
        while ((*format >= '0' && *format <= '9')
               || *format == '-' || *format == ' ' || *format == '.')
          format++;
@@ -1811,7 +1810,7 @@ Use %% to put a single % into the output.")
        if (*format == '%')
          format++;
        else if (++n >= nargs)
-         error ("not enough arguments for format string");
+         error ("Not enough arguments for format string");
        else if (*format == 'S')
          {
            /* For `S', prin1 the argument and then treat like a string.  */
@@ -1831,6 +1830,10 @@ Use %% to put a single % into the output.")
            if (*format != 's' && *format != 'S')
              error ("format specifier doesn't match argument type");
            total += XSTRING (args[n])->size;
+           /* We have to put an arbitrary limit on minlen
+              since otherwise it could make alloca fail.  */
+           if (minlen < XSTRING (args[n])->size + 1000)
+             total += minlen;
          }
        /* Would get MPV otherwise, since Lisp_Int's `point' to low memory.  */
        else if (INTEGERP (args[n]) && *format != 's')
@@ -1844,6 +1847,10 @@ Use %% to put a single % into the output.")
              args[n] = Ffloat (args[n]);
 #endif
            total += 30;
+           /* We have to put an arbitrary limit on minlen
+              since otherwise it could make alloca fail.  */
+           if (minlen < 1000)
+             total += minlen;
          }
 #ifdef LISP_FLOAT_TYPE
        else if (FLOATP (args[n]) && *format != 's')
@@ -1851,6 +1858,10 @@ Use %% to put a single % into the output.")
            if (! (*format == 'e' || *format == 'f' || *format == 'g'))
              args[n] = Ftruncate (args[n]);
            total += 30;
+           /* We have to put an arbitrary limit on minlen
+              since otherwise it could make alloca fail.  */
+           if (minlen < 1000)
+             total += minlen;
          }
 #endif
        else