photomosaics

commit 8bf5bfcd8caa1dd8a88341c7a3795882e8486a27
parent 30662c5b3c8fe5dcd7a416163396e5a4e08cb2cb
Author: Wilson Gheen <wilson@wilsonrgheen.com>
Date:   Tue, 17 Jan 2023 15:52:42 -0600

Isolate errno in `parse_num` from possible errors in `setlocale`

Diffstat:
M
photomosaics.c
 | 
5
+++--

1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/photomosaics.c b/photomosaics.c
@@ -53,8 +53,8 @@ static bool parse_num(const char *str, NUM_TYPES type, void *out) {
     char *endptr;
     const char *old_locale = setlocale(LC_ALL, NULL);
     setlocale(LC_ALL|~LC_NUMERIC, "");
-    errno = 0;
     int my_errno = 0;
+    errno = 0;
 
     switch(type) {
     case L:
@@ -77,8 +77,9 @@ static bool parse_num(const char *str, NUM_TYPES type, void *out) {
         break;
     }
 
+    int their_errno = errno;
     setlocale(LC_ALL, old_locale);
-    if(errno) return false;
+    if((errno=their_errno)) return false;
     if(my_errno) { 
         errno = my_errno;
         return false;