Provide workaround in nsPageMgr.cpp if platform (HPUX) doesn't have /dev/zero.

briano, ramiro & warren all looked at the code.

(also sneaked in a linking option in for hpux only)

configure.in

@@ -579,7 +579,7 @@ case "$target" in
 *-hpux*)
     DLL_SUFFIX="sl"
     if test ! "$GNU_CC"; then
-	DSO_LDOPTS='-b -E -L$(DIST)/bin'
+	DSO_LDOPTS='-b -E +s -L$(DIST)/bin'
 	DSO_CFLAGS=""
 	DSO_PIC_CFLAGS="+Z"
     else
@@ -1802,6 +1802,34 @@ else
   AC_MSG_RESULT(unknown)
 fi
 
+dnl Figure out how to 'allocate' paged memory areas (see xpcom/ds/nsPageMgr.cpp)
+dnl First see if /dev/zero is supported so that we
+dnl can mmap against it.  If not (hpux) then see if
+dnl if valloc is supported (which is hpux's malloc
+dnl on paged memory boundary
+dnl ========================================================
+
+AC_MSG_CHECKING(for /dev/zero)
+if test -f /dev/zero; then
+  AC_DEFINE(HAVE_DEV_ZERO)
+  AC_MSG_RESULT(yes)
+else
+        AC_MSG_RESULT(no)
+        AC_MSG_CHECKING(for valloc)
+        AC_CACHE_VAL(ac_cv_valloc,
+                     [AC_TRY_COMPILE([#include <stdlib.h>],
+                                     [void *ptr = valloc(1);],
+                                     [ac_cv_valloc=true],
+                                     [ac_cv_valloc=false])])
+
+	if test "$ac_cv_valloc" = true ; then
+	  AC_DEFINE(HAVE_VALLOC)
+	  AC_MSG_RESULT(yes)
+	else
+	  AC_MSG_RESULT(no)
+	fi
+fi
+
 dnl Check for dll-challenged libc's.
 dnl This check is apparently only needed for Linux.
 case "$target" in

xpcom/ds/nsPageMgr.cpp

@@ -400,10 +400,10 @@ nsPageMgr::InitPages(nsPageCount minPages, nsPageCount maxPages)
     nsPageCount size = maxPages;
     mZero_fd = NULL;
 
+#ifdef HAVE_DEV_ZERO
     mZero_fd = open("/dev/zero", O_RDWR);
-
     while (addr == NULL) {
-        /* let the system place the heap */
+    /* let the system place the heap */
         addr = (nsPage*)mmap(0, size << NS_PAGEMGR_PAGE_BITS,
                              PROT_READ | PROT_WRITE,
                              MAP_PRIVATE,
@@ -416,6 +416,21 @@ nsPageMgr::InitPages(nsPageCount minPages, nsPageCount maxPages)
             }
         }
     }
+#else
+#ifdef HAVE_VALLOC 
+    while (addr == NULL) {
+        addr = (nsPage*)valloc(size << NS_PAGEMGR_PAGE_BITS);
+        if (NULL == addr) {
+            size--;
+            if (size < minPages) {
+                return PR_FAILURE;
+            }
+        }
+    }
+    memset(addr, '\0', size << NS_PAGEMGR_PAGE_BITS);
+#endif /* HAVE_VALLOC */
+#endif /* HAVE_DEV_ZERO */
+
     PR_ASSERT(NS_PAGEMGR_IS_ALIGNED(addr, NS_PAGEMGR_PAGE_BITS));
     mMemoryBase = addr;
     mPageCount = size;
@@ -464,8 +479,14 @@ nsPageMgr::FinalizePages()
     sys$deltva(&retadr,&retadr2,0);
 
 #else
+#ifdef HAVE_DEV_ZERO
     munmap((caddr_t)mMemoryBase, mPageCount << NS_PAGEMGR_PAGE_BITS);
     close(mZero_fd);
+#else /* HAVE_DEV_ZERO */
+#ifdef HAVE_VALLOC
+    free(mMemoryBase);
+#endif /* HAVE_VALLOC */
+#endif /* HAVE_DEV_ZERO */
 #endif
 }