Prevent grn from core dumping when given more than 50 command lines

arguments (CR #17621259).

This fix is not currently in the latest groff sources, and has been passed

upstream.

--- groff-1.22.2/src/preproc/grn/main.cpp.orig	2014-01-23 16:54:20.488279600 -0800

+++ groff-1.22.2/src/preproc/grn/main.cpp	2014-01-23 16:58:22.672837243 -0800

@@ -92,6 +92,8 @@

 extern POINT *PTInit();

 extern POINT *PTMakePoint(double x, double y, POINT **pplist);

+#define INIT_FILE_SIZE 50  /* Initial size of array of files from cmd line. */

+#define FILE_SIZE_INCR 50  /* Amount to increase array of files by. */

 #define SUN_SCALEFACTOR 0.70

@@ -244,6 +246,25 @@

 }

+/* Add a new file entry in the array, expanding array if needs be. */

+

+char **

+add_file(char **file, char *new_file, int *count, int *cur_size)

+{

+  if (*count >= *cur_size) {

+    *cur_size += FILE_SIZE_INCR;

+    file = (char **) realloc((char **) file, *cur_size * sizeof(char *));

+    if (file == NULL) {

+      fatal("unable to extend file array");

+    }

+  }

+  file[*count] = new_file;

+  *count += 1;

+

+  return file;

+}

+

+

 /*----------------------------------------------------------------------------*

  | Routine:	main (argument_count, argument_pointer)

  |

@@ -262,18 +283,22 @@

   register FILE *fp;

   register int k;

   register char c;

-  register int gfil = 0;

-  char *file[50];

+  int gfil = 0;

+  char **file = NULL;

+  int file_cur_size = INIT_FILE_SIZE;

   char *operand(int *argcp, char ***argvp);

+  if ((file = (char **) malloc(file_cur_size * sizeof(char *))) == NULL) {

+    fatal("unable to create file array");

+  }

   while (--argc) {

     if (**++argv != '-')

-      file[gfil++] = *argv;

+      file = add_file(file, *argv, &gfil, &file_cur_size);

     else

       switch (c = (*argv)[1]) {

       case 0:

-	file[gfil++] = NULL;

+	file = add_file(file, NULL, &gfil, &file_cur_size);

 	break;

       case 'C':		/* compatibility mode */