Added a workaround for a broken (or old) implementation of realpath.

Part of the fix for #806.

configure.ac

@@ -54,6 +54,8 @@ AX_CHECK_LINK_FLAG([-pie], [LDFLAGS+=" -pie"])
 
 AC_HEADER_STDC
 
+gl_CANONICALIZE_LGPL
+
 # linux has integer types in stdint.h, solaris, vms in inttypes.h
 AC_CHECK_HEADERS([stdint.h])
 AC_CHECK_HEADERS([stdalign.h])

m4/00gnulib.m4

@@ -0,0 +1,46 @@
+# 00gnulib.m4 serial 3
+dnl Copyright (C) 2009-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl This file must be named something that sorts before all other
+dnl gnulib-provided .m4 files.  It is needed until such time as we can
+dnl assume Autoconf 2.64, with its improved AC_DEFUN_ONCE and
+dnl m4_divert semantics.
+
+# Until autoconf 2.63, handling of the diversion stack required m4_init
+# to be called first; but this does not happen with aclocal.  Wrapping
+# the entire execution in another layer of the diversion stack fixes this.
+# Worse, prior to autoconf 2.62, m4_wrap depended on the underlying m4
+# for whether it was FIFO or LIFO; in order to properly balance with
+# m4_init, we need to undo our push just before anything wrapped within
+# the m4_init body.  The way to ensure this is to wrap both sides of
+# m4_init with a one-shot macro that does the pop at the right time.
+m4_ifndef([_m4_divert_diversion],
+[m4_divert_push([KILL])
+m4_define([gl_divert_fixup], [m4_divert_pop()m4_define([$0])])
+m4_define([m4_init],
+  [gl_divert_fixup()]m4_defn([m4_init])[gl_divert_fixup()])])
+
+
+# AC_DEFUN_ONCE([NAME], VALUE)
+# ----------------------------
+# Define NAME to expand to VALUE on the first use (whether by direct
+# expansion, or by AC_REQUIRE), and to nothing on all subsequent uses.
+# Avoid bugs in AC_REQUIRE in Autoconf 2.63 and earlier.  This
+# definition is slower than the version in Autoconf 2.64, because it
+# can only use interfaces that existed since 2.59; but it achieves the
+# same effect.  Quoting is necessary to avoid confusing Automake.
+m4_version_prereq([2.63.263], [],
+[m4_define([AC][_DEFUN_ONCE],
+  [AC][_DEFUN([$1],
+    [AC_REQUIRE([_gl_DEFUN_ONCE([$1])],
+      [m4_indir([_gl_DEFUN_ONCE([$1])])])])]dnl
+[AC][_DEFUN([_gl_DEFUN_ONCE([$1])], [$2])])])
+
+# gl_00GNULIB
+# -----------
+# Witness macro that this file has been included.  Needed to force
+# Automake to include this file prior to all other gnulib .m4 files.
+AC_DEFUN([gl_00GNULIB])

m4/canonicalize.m4

@@ -0,0 +1,124 @@
+# canonicalize.m4 serial 26
+
+dnl Copyright (C) 2003-2007, 2009-2016 Free Software Foundation, Inc.
+
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Provides canonicalize_file_name and canonicalize_filename_mode, but does
+# not provide or fix realpath.
+AC_DEFUN([gl_FUNC_CANONICALIZE_FILENAME_MODE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+  else
+    case "$gl_cv_func_realpath_works" in
+      *yes) ;;
+      *)    REPLACE_CANONICALIZE_FILE_NAME=1 ;;
+    esac
+  fi
+])
+
+# Provides canonicalize_file_name and realpath.
+AC_DEFUN([gl_CANONICALIZE_LGPL],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+  AC_REQUIRE([gl_CANONICALIZE_LGPL_SEPARATE])
+  if test $ac_cv_func_canonicalize_file_name = no; then
+    HAVE_CANONICALIZE_FILE_NAME=0
+    if test $ac_cv_func_realpath = no; then
+      HAVE_REALPATH=0
+    else
+      case "$gl_cv_func_realpath_works" in
+	*yes) ;;
+	*)    REPLACE_REALPATH=1 ;;
+      esac
+    fi
+  else
+    case "$gl_cv_func_realpath_works" in
+      *yes)
+        ;;
+      *)
+        REPLACE_CANONICALIZE_FILE_NAME=1
+        REPLACE_REALPATH=1
+        ;;
+    esac
+  fi
+])
+
+# Like gl_CANONICALIZE_LGPL, except prepare for separate compilation
+# (no REPLACE_CANONICALIZE_FILE_NAME, no REPLACE_REALPATH, no AC_LIBOBJ).
+AC_DEFUN([gl_CANONICALIZE_LGPL_SEPARATE],
+[
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_CHECK_FUNCS_ONCE([canonicalize_file_name getcwd readlink])
+  AC_REQUIRE([gl_DOUBLE_SLASH_ROOT])
+  AC_REQUIRE([gl_FUNC_REALPATH_WORKS])
+  AC_CHECK_HEADERS_ONCE([sys/param.h])
+])
+
+# Check whether realpath works.  Assume that if a platform has both
+# realpath and canonicalize_file_name, but the former is broken, then
+# so is the latter.
+AC_DEFUN([gl_FUNC_REALPATH_WORKS],
+[
+  AC_CHECK_FUNCS_ONCE([realpath])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether realpath works], [gl_cv_func_realpath_works], [
+    touch conftest.a
+    mkdir conftest.d
+    AC_RUN_IFELSE([
+      AC_LANG_PROGRAM([[
+        ]GL_NOCRASH[
+        #include <stdlib.h>
+        #include <string.h>
+      ]], [[
+        int result = 0;
+        {
+          char *name = realpath ("conftest.a", NULL);
+          if (!(name && *name == '/'))
+            result |= 1;
+        }
+        {
+          char *name = realpath ("conftest.b/../conftest.a", NULL);
+          if (name != NULL)
+            result |= 2;
+        }
+        {
+          char *name = realpath ("conftest.a/", NULL);
+          if (name != NULL)
+            result |= 4;
+        }
+        {
+          char *name1 = realpath (".", NULL);
+          char *name2 = realpath ("conftest.d//./..", NULL);
+          if (strcmp (name1, name2) != 0)
+            result |= 8;
+        }
+        return result;
+      ]])
+     ],
+     [gl_cv_func_realpath_works=yes],
+     [gl_cv_func_realpath_works=no],
+     [case "$host_os" in
+                       # Guess yes on glibc systems.
+        *-gnu* | gnu*) gl_cv_func_realpath_works="guessing yes" ;;
+                       # If we don't know, assume the worst.
+        *)             gl_cv_func_realpath_works="guessing no" ;;
+      esac
+     ])
+    rm -rf conftest.a conftest.d
+  ])
+  case "$gl_cv_func_realpath_works" in
+    *yes)
+      AC_DEFINE([FUNC_REALPATH_WORKS], [1], [Define to 1 if realpath()
+        can malloc memory, always gives an absolute path, and handles
+        trailing slash correctly.])
+      ;;
+  esac
+])

m4/double-slash-root.m4

@@ -0,0 +1,38 @@
+# double-slash-root.m4 serial 4   -*- Autoconf -*-
+dnl Copyright (C) 2006, 2008-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_DOUBLE_SLASH_ROOT],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CACHE_CHECK([whether // is distinct from /], [gl_cv_double_slash_root],
+    [ if test x"$cross_compiling" = xyes ; then
+        # When cross-compiling, there is no way to tell whether // is special
+        # short of a list of hosts.  However, the only known hosts to date
+        # that have a distinct // are Apollo DomainOS (too old to port to),
+        # Cygwin, and z/OS.  If anyone knows of another system for which // has
+        # special semantics and is distinct from /, please report it to
+        # <[email protected]>.
+        case $host in
+          *-cygwin | i370-ibm-openedition)
+            gl_cv_double_slash_root=yes ;;
+          *)
+            # Be optimistic and assume that / and // are the same when we
+            # don't know.
+            gl_cv_double_slash_root='unknown, assuming no' ;;
+        esac
+      else
+        set x `ls -di / // 2>/dev/null`
+        if test "$[2]" = "$[4]" && wc //dev/null >/dev/null 2>&1; then
+          gl_cv_double_slash_root=no
+        else
+          gl_cv_double_slash_root=yes
+        fi
+      fi])
+  if test "$gl_cv_double_slash_root" = yes; then
+    AC_DEFINE([DOUBLE_SLASH_IS_DISTINCT_ROOT], [1],
+      [Define to 1 if // is a file system root distinct from /.])
+  fi
+])

m4/nocrash.m4

@@ -0,0 +1,130 @@
+# nocrash.m4 serial 4
+dnl Copyright (C) 2005, 2009-2016 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Based on libsigsegv, from Bruno Haible and Paolo Bonzini.
+
+AC_PREREQ([2.13])
+
+dnl Expands to some code for use in .c programs that will cause the configure
+dnl test to exit instead of crashing. This is useful to avoid triggering
+dnl action from a background debugger and to avoid core dumps.
+dnl Usage:   ...
+dnl          ]GL_NOCRASH[
+dnl          ...
+dnl          int main() { nocrash_init(); ... }
+AC_DEFUN([GL_NOCRASH],[[
+#include <stdlib.h>
+#if defined __MACH__ && defined __APPLE__
+/* Avoid a crash on Mac OS X.  */
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <mach/thread_status.h>
+#include <mach/exception.h>
+#include <mach/task.h>
+#include <pthread.h>
+/* The exception port on which our thread listens.  */
+static mach_port_t our_exception_port;
+/* The main function of the thread listening for exceptions of type
+   EXC_BAD_ACCESS.  */
+static void *
+mach_exception_thread (void *arg)
+{
+  /* Buffer for a message to be received.  */
+  struct {
+    mach_msg_header_t head;
+    mach_msg_body_t msgh_body;
+    char data[1024];
+  } msg;
+  mach_msg_return_t retval;
+  /* Wait for a message on the exception port.  */
+  retval = mach_msg (&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE, 0, sizeof (msg),
+                     our_exception_port, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+  if (retval != MACH_MSG_SUCCESS)
+    abort ();
+  exit (1);
+}
+static void
+nocrash_init (void)
+{
+  mach_port_t self = mach_task_self ();
+  /* Allocate a port on which the thread shall listen for exceptions.  */
+  if (mach_port_allocate (self, MACH_PORT_RIGHT_RECEIVE, &our_exception_port)
+      == KERN_SUCCESS) {
+    /* See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/mach_port_insert_right.html.  */
+    if (mach_port_insert_right (self, our_exception_port, our_exception_port,
+                                MACH_MSG_TYPE_MAKE_SEND)
+        == KERN_SUCCESS) {
+      /* The exceptions we want to catch.  Only EXC_BAD_ACCESS is interesting
+         for us.  */
+      exception_mask_t mask = EXC_MASK_BAD_ACCESS;
+      /* Create the thread listening on the exception port.  */
+      pthread_attr_t attr;
+      pthread_t thread;
+      if (pthread_attr_init (&attr) == 0
+          && pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED) == 0
+          && pthread_create (&thread, &attr, mach_exception_thread, NULL) == 0) {
+        pthread_attr_destroy (&attr);
+        /* Replace the exception port info for these exceptions with our own.
+           Note that we replace the exception port for the entire task, not only
+           for a particular thread.  This has the effect that when our exception
+           port gets the message, the thread specific exception port has already
+           been asked, and we don't need to bother about it.
+           See http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/task_set_exception_ports.html.  */
+        task_set_exception_ports (self, mask, our_exception_port,
+                                  EXCEPTION_DEFAULT, MACHINE_THREAD_STATE);
+      }
+    }
+  }
+}
+#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Avoid a crash on native Windows.  */
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <winerror.h>
+static LONG WINAPI
+exception_filter (EXCEPTION_POINTERS *ExceptionInfo)
+{
+  switch (ExceptionInfo->ExceptionRecord->ExceptionCode)
+    {
+    case EXCEPTION_ACCESS_VIOLATION:
+    case EXCEPTION_IN_PAGE_ERROR:
+    case EXCEPTION_STACK_OVERFLOW:
+    case EXCEPTION_GUARD_PAGE:
+    case EXCEPTION_PRIV_INSTRUCTION:
+    case EXCEPTION_ILLEGAL_INSTRUCTION:
+    case EXCEPTION_DATATYPE_MISALIGNMENT:
+    case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
+    case EXCEPTION_NONCONTINUABLE_EXCEPTION:
+      exit (1);
+    }
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+static void
+nocrash_init (void)
+{
+  SetUnhandledExceptionFilter ((LPTOP_LEVEL_EXCEPTION_FILTER) exception_filter);
+}
+#else
+/* Avoid a crash on POSIX systems.  */
+#include <signal.h>
+/* A POSIX signal handler.  */
+static void
+exception_handler (int sig)
+{
+  exit (1);
+}
+static void
+nocrash_init (void)
+{
+#ifdef SIGSEGV
+  signal (SIGSEGV, exception_handler);
+#endif
+#ifdef SIGBUS
+  signal (SIGBUS, exception_handler);
+#endif
+}
+#endif
+]])

src/gregorio-utils.c

@@ -67,8 +67,16 @@ typedef enum gregorio_file_format {
 /* _MAX_PATH is being passed for the maxLength (third) argument of _fullpath,
  * but we are always passing NULL for the absPath (first) argument, so it will
  * be ignored per the MSDN documentation */
-#define realpath(path,resolved_path) _fullpath(resolved_path, path, _MAX_PATH)
-#endif
+#define gregorio_realpath(path,resolved_path) _fullpath(resolved_path,path,_MAX_PATH)
+#else
+#ifdef FUNC_REALPATH_WORKS
+#define gregorio_realpath(path,resolved_path) realpath(path,resolved_path)
+#else
+/* When realpath doesn't work (on an older system), we are forced to use
+ * PATH_MAX to allocate a buffer */
+#define gregorio_realpath(path,resolved_path) realpath(path,gregorio_malloc(PATH_MAX))
+#endif /* FUNC_REALPATH_WORKS */
+#endif /* _WIN32 */
 
 /* define_path attempts to canonicalize the pathname of a given string */
 static char *define_path(char *current_directory, char *string)
@@ -96,7 +104,7 @@ static char *define_path(char *current_directory, char *string)
         base_name++;
 
         /* try to resolve it */
-        file_name = realpath(temp_name, NULL);
+        file_name = gregorio_realpath(temp_name, NULL);
         if (!file_name) {
             fprintf(stderr, "the directory %s for %s does not exist\n",
                     temp_name, base_name);
@@ -238,7 +246,7 @@ static char *encode_point_and_click_filename(char *input_file_name)
     static const char *const hex = "0123456789ABCDEF";
     char *filename, *result = NULL, *r = NULL, *p;
 
-    filename = realpath(input_file_name, NULL);
+    filename = gregorio_realpath(input_file_name, NULL);
     if (!filename) {
         fprintf(stderr, "error: unable to resolve %s\n", input_file_name);
         exit(1);