https://lists.gnu.org/archive/html/info-mtools/2022-03/msg00001.html

From d36dea2ea7f246f28719dcb01b7a8ad7ad8ed1f6 Mon Sep 17 00:00:00 2001
From: Sam James <sam@gentoo.org>
Date: Sun, 6 Mar 2022 02:36:03 +0000
Subject: [PATCH] Use own definition of strtoi
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Before this change, build resulted in implicit function declarations like:
```
* config.c:269:57: warning: implicit declaration of function ‘strtoi’; did you mean ‘strtoui’? [-Wimplicit-function-declaration]
* floppyd_io.c:473:20: warning: implicit declaration of function ‘strtoi’; did you mean ‘strtoui’? [-Wimplicit-function-declaration]
```

The include(s) for inttypes.h are guarded by HAVE_INTTYPES_H
(normal autoconf pattern) but we're not checking for inttypes.h
in configure. But adding this doesn't solve the issue.

If libbsd is installed, configure discovers the strtoi
provided by libbsd  although the included version may still
end up being glibc's as the include path doesn't change
(glibc has its own which doesn't feature strtoi).

If trying to use libbsd's, we end up with a build failure:
```
config.c: In function ‘get_env_conf’:
config.c:269:57: error: too few arguments to function ‘strtoi’
  269 |                 * ((int *)global_switches[i].address) = strtoi(s,0,0);
      |                                                         ^~~~~~
In file included from sysincludes.h:174,
                 from config.c:18:
/usr/include/bsd/inttypes.h:43:10: note: declared here
   43 | intmax_t strtoi(const char *__restrict nptr, char **__restrict endptr,
      |          ^~~~~~
```

So, it seems best to just always use our own definition of strtoi,
given our definition doesn't match libbsd's anyway. This avoids
the build failure as well as the implicit declaration warnings.

Signed-off-by: Sam James <sam@gentoo.org>
---
 configure.in  | 2 +-
 mtools.h      | 2 --
 sysincludes.h | 4 ----
 3 files changed, 1 insertions(+), 7 deletions(-)

diff --git a/configure.in b/configure.in
index 72cf205..eb1c754 100644
--- a/configure.in
+++ b/configure.in
@@ -218,7 +218,7 @@ dnl Checks for library functions.
 AC_TYPE_SIGNAL
 AC_CHECK_FUNCS(strerror random srandom strchr strrchr lockf flock \
 strcasecmp strncasecmp strnlen atexit on_exit getpass memmove \
-strdup strndup strcspn strspn strtoul strtol strtoll strtoi strtoui \
+strdup strndup strcspn strspn strtoul strtol strtoll strtoui \
 memcpy strpbrk memset setenv seteuid setresuid setpgrp \
 tcsetattr tcflush basename fchdir media_oldaliases  \
 snprintf setlocale toupper_l strncasecmp_l \
diff --git a/mtools.h b/mtools.h
index b3fd3c8..190ddf8 100644
--- a/mtools.h
+++ b/mtools.h
@@ -188,9 +188,7 @@ off_t str_to_offset(char *str);
 uint32_t parseSize(char *sizeStr);
 unsigned int strtoui(const char *nptr, char **endptr, int base);
 unsigned int atoui(const char *nptr);
-#ifndef HAVE_STRTOI
 int strtoi(const char *nptr, char **endptr, int base);
-#endif
 unsigned long atoul(const char *nptr);
 uint8_t strtou8(const char *nptr, char **endptr, int base);
 uint8_t atou8(const char *str);
diff --git a/sysincludes.h b/sysincludes.h
index 6dccded..0c17fb5 100644
--- a/sysincludes.h
+++ b/sysincludes.h
@@ -169,10 +169,6 @@ typedef unsigned char _Bool;
 # define __bool_true_false_are_defined 1
 #endif
 
-#ifdef HAVE_INTTYPES_H
-# include <inttypes.h>
-#endif
-
 #ifdef HAVE_STDLIB_H
 # include <stdlib.h>
 #endif
-- 
2.35.1