[nongnu] elpa/pdf-tools 8ee31220a6 1/2: Revert "Use mkstemp instead of tempnam"

[ELPA Syncer]

branch: elpa/pdf-tools
commit 8ee31220a6ae3e41549bfffca7a89c481d270004
Author: Vedang Manerikar <ved.manerikar@gmail.com>
Commit: Vedang Manerikar <ved.manerikar@gmail.com>

    Revert "Use mkstemp instead of tempnam"
    
    This reverts commit d63a1e7d87f9b0a19209f2eeb170bcf64612aa2f.
    
    In d63a1e7, @JunyuanChen fixed a long standing compilation warning by
    replacing `tempnam` with `mkstemp` in `epdfinfo`. However, the
    `mkstemp` implementation does not work correctly on MS
    Windows (probably because the path template is "wrong" for Windows).
    
    I am reverting the commit and opening a new issue #110 to track the
    correct implementation of `mkstemp` (or equivalent) on MS Windows.
    
    It would also be great to add a test against Windows CI to open a PDF
    and check that the operation completes successfully.
    
    Closes: #101
---
 server/epdfinfo.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/server/epdfinfo.c b/server/epdfinfo.c
index 95a7f1628a..3e0e7c1166 100644
--- a/server/epdfinfo.c
+++ b/server/epdfinfo.c
@@ -35,7 +35,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <unistd.h>
 #include <errno.h>
 #include <png.h>
 #include <math.h>
@@ -347,18 +346,26 @@ strchomp (char *str)
 static char*
 mktempfile()
 {
-  char template[] = "/tmp/epdfinfoXXXXXX";
-  char *filename = malloc(sizeof(template));
-  memcpy(filename, template, sizeof(template));
-  int fd = mkstemp(filename);
-  if (fd == -1)
+  char *filename = NULL;
+  int tries = 3;
+  while (! filename && tries-- > 0)
     {
-      fprintf (stderr, "Unable to create tempfile");
-      free(filename);
-      filename = NULL;
+
+      filename =  tempnam(NULL, "epdfinfo");
+      if (filename)
+        {
+          int fd = open(filename, O_CREAT | O_EXCL | O_RDONLY, S_IRWXU);
+          if (fd > 0)
+            close (fd);
+          else
+            {
+              free (filename);
+              filename = NULL;
+            }
+        }
     }
-  else
-    close(fd);
+  if (! filename)
+    fprintf (stderr, "Unable to create tempfile");
 
   return filename;
 }