Include <stdlib.h> unconditionally.

(getusershell, setusershell, endusershell, readname, main):
Define with prototypes.

(readname, default_index, line_size, readname):
Use size_t, not int, for sizes.
(readname): If the size overflows, report an error instead of
looping forever.

1 files changed, 20 insertions, 19 deletions

diff --git a/lib/getusershell.c b/lib/getusershell.c
index 3401c885d..c026ec0a9 100644
--- a/lib/getusershell.c
+++ b/lib/getusershell.c
@@ -32,9 +32,7 @@
 #endif
 
 #include <stdio.h>
-#if HAVE_STDLIB_H
-# include <stdlib.h>
-#endif
+#include <stdlib.h>
 #include <ctype.h>
 #include "unlocked-io.h"
 #include "xalloc.h"
@@ -47,7 +45,7 @@
 
 #define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
 
-static int readname ();
+static size_t readname (char **, size_t *, FILE *);
 
 #if ! defined ADDITIONAL_DEFAULT_SHELLS && defined __MSDOS__
 # define ADDITIONAL_DEFAULT_SHELLS \
@@ -65,7 +63,7 @@ static char const* const default_shells[] =
 
 /* Index of the next shell in `default_shells' to return.
    0 means we are not using `default_shells'. */
-static int default_index = 0;
+static size_t default_index = 0;
 
 /* Input stream from the shells file. */
 static FILE *shellstream = NULL;
@@ -74,7 +72,7 @@ static FILE *shellstream = NULL;
 static char *line = NULL;
 
 /* Number of bytes allocated for `line'. */
-static int line_size = 0;
+static size_t line_size = 0;
 
 /* Return an entry from the shells file, ignoring comment lines.
    If the file doesn't exist, use the list in DEFAULT_SHELLS (above).
@@ -82,7 +80,7 @@ static int line_size = 0;
    Return NULL if there are no more entries.  */
 
 char *
-getusershell ()
+getusershell (void)
 {
   if (default_index > 0)
     {
@@ -114,7 +112,7 @@ getusershell ()
 /* Rewind the shells file. */
 
 void
-setusershell ()
+setusershell (void)
 {
   default_index = 0;
   if (shellstream)
@@ -124,7 +122,7 @@ setusershell ()
 /* Close the shells file. */
 
 void
-endusershell ()
+endusershell (void)
 {
   if (shellstream)
     {
@@ -138,21 +136,21 @@ endusershell ()
    and/or realloc'd as necessary and can start out NULL,
    and whose size is passed and returned in *SIZE.
 
-   Return the number of characters placed in *NAME
+   Return the number of bytes placed in *NAME
    if some nonempty sequence was found, otherwise 0.  */
 
-static int
-readname (name, size, stream)
-     char **name;
-     int *size;
-     FILE *stream;
+static size_t
+readname (char **name, size_t *size, FILE *stream)
 {
   int c;
-  int name_index = 0;
+  size_t name_index = 0;
 
   if (*name == NULL)
     {
-      *size = 10;
+      /* The initial size must be a power of two, so that the overflow
+	 check works.  */
+      *size = 16;
+
       *name = xmalloc (*size);
     }
 
@@ -163,9 +161,11 @@ readname (name, size, stream)
   while (c != EOF && !ISSPACE (c))
     {
       (*name)[name_index++] = c;
-      while (name_index >= *size)
+      if (*size < name_index)
 	{
 	  *size *= 2;
+	  if (! *size)
+	    xalloc_die ();
 	  *name = xrealloc (*name, *size);
 	}
       c = getc (stream);
@@ -175,7 +175,8 @@ readname (name, size, stream)
 }
 
 #ifdef TEST
-main ()
+int
+main (void)
 {
   char *s;