From fe9fdd4fc3221e581860aac3ffcd6f5595911557 Mon Sep 17 00:00:00 2001
From: Peter Kokot <peterkokot@gmail.com>
Date: Mon, 22 Jul 2024 10:00:14 +0200
Subject: [PATCH] Autotools: Fix unused result and variables warnings in flush
 IO check (#15056)

- exit() replaced with regular return since these two behave the same in
  main()
- main(void) used as argc and argv aren't used
- if sentences wrapped in curly brackets for readability
- fgets wrapped in if to check for the return result and omit the
  "ignoring return value of 'fgets' declared with attribute
  'warn_unused_result'..." warnings in the config.log
- fclose(fp) added before returning
---
 ext/standard/config.m4 | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/ext/standard/config.m4 b/ext/standard/config.m4
index b055af732a8..49ae2c7e326 100644
--- a/ext/standard/config.m4
+++ b/ext/standard/config.m4
@@ -11,35 +11,55 @@ AC_CACHE_CHECK([whether flush should be called explicitly after a buffered io],
 #endif
 #include <string.h>
 
-int main(int argc, char **argv)
+int main(void)
 {
   char *filename = tmpnam(NULL);
   char buffer[64];
   int result = 0;
 
   FILE *fp = fopen(filename, "wb");
-  if (NULL == fp)
+  if (NULL == fp) {
     return 0;
+  }
+
   fputs("line 1\n", fp);
   fputs("line 2\n", fp);
   fclose(fp);
 
   fp = fopen(filename, "rb+");
-  if (NULL == fp)
+  if (NULL == fp) {
     return 0;
-  fgets(buffer, sizeof(buffer), fp);
+  }
+
+  if (fgets(buffer, sizeof(buffer), fp) == NULL) {
+    fclose(fp);
+    return 0;
+  }
+
   fputs("line 3\n", fp);
   rewind(fp);
-  fgets(buffer, sizeof(buffer), fp);
-  if (0 != strcmp(buffer, "line 1\n"))
+  if (fgets(buffer, sizeof(buffer), fp) == NULL) {
+    fclose(fp);
+    return 0;
+  }
+
+  if (0 != strcmp(buffer, "line 1\n")) {
     result = 1;
-  fgets(buffer, sizeof(buffer), fp);
-  if (0 != strcmp(buffer, "line 3\n"))
+  }
+
+  if (fgets(buffer, sizeof(buffer), fp) == NULL) {
+    fclose(fp);
+    return 0;
+  }
+
+  if (0 != strcmp(buffer, "line 3\n")) {
     result = 1;
+  }
+
   fclose(fp);
   unlink(filename);
 
-  exit(result);
+  return result;
 }
 ]])],
 [php_cv_have_flush_io=no],