readutmp, boot-time: Fix parsing of /proc/uptime

[Bruno Haible]

/proc/uptime contains a floating-point number with '.' as decimal separator.
It thus needs to be parsed with 'c_strtod', not 'strtod' (which expects a ','
on French and German locales).


2023-08-12  Bruno Haible  <bruno@clisp.org>

        readutmp, boot-time: Fix parsing of /proc/uptime.
        * lib/boot-time-aux.h (get_linux_uptime): Use c_strtod, not strtod.
        * lib/readutmp.c: Include c-strtod.h.
        * lib/boot-time.c: Likewise.
        * modules/readutmp (Depends-on): Add c-strtod.
        * modules/boot-time (Depends-on): Likewise.

diff --git a/lib/boot-time-aux.h b/lib/boot-time-aux.h
index e9f58e9d7e..4c5474c6c8 100644
--- a/lib/boot-time-aux.h
+++ b/lib/boot-time-aux.h
@@ -48,7 +48,7 @@ get_linux_uptime (struct timespec *p_uptime)
           buf[n] = '\0';
           /* buf now contains two values: the uptime and the idle time.  */
           char *endptr;
-          double uptime = strtod (buf, &endptr);
+          double uptime = c_strtod (buf, &endptr);
           if (endptr > buf)
             {
               p_uptime->tv_sec = (time_t) uptime;
diff --git a/lib/boot-time.c b/lib/boot-time.c
index d813bfa582..339ee8e938 100644
--- a/lib/boot-time.c
+++ b/lib/boot-time.c
@@ -43,6 +43,7 @@
 # include <OS.h>
 #endif
 
+#include "c-strtod.h"
 #include "idx.h"
 #include "readutmp.h"
 #include "stat-time.h"
diff --git a/lib/readutmp.c b/lib/readutmp.c
index ef9f0aff43..6054511edf 100644
--- a/lib/readutmp.c
+++ b/lib/readutmp.c
@@ -51,6 +51,7 @@
 # include <OS.h>
 #endif
 
+#include "c-strtod.h"
 #include "stat-time.h"
 #include "xalloc.h"
 
diff --git a/modules/boot-time b/modules/boot-time
index ba8a2b4e6f..8890406d6c 100644
--- a/modules/boot-time
+++ b/modules/boot-time
@@ -9,6 +9,7 @@ lib/readutmp.h
 m4/readutmp.m4
 
 Depends-on:
+c-strtod
 extensions
 fopen-gnu
 idx
diff --git a/modules/readutmp b/modules/readutmp
index 85bbf74954..fcbc7ff149 100644
--- a/modules/readutmp
+++ b/modules/readutmp
@@ -9,6 +9,7 @@ m4/readutmp.m4
 m4/systemd.m4
 
 Depends-on:
+c-strtod
 extensions
 fopen-gnu
 idx