3 files changed, 135 insertions, 8 deletions

diff --git a/doc/HISTORY b/doc/HISTORY
index 3191200b..8835b686 100644
--- a/doc/HISTORY
+++ b/doc/HISTORY
@@ -8,6 +8,11 @@ not yet  BJH  Release 10.70.00
 
               Add yuy2topam.  Thanks Michael Haardt.
 
+              On Windows, don't leave temporary files around (previous code
+              did so because unlink of an open file fails in Windows; new
+              code deletes temporary files via atexit).  Thanks
+              Ludolf Holzheid <ludolf.holzheid@gmx.de>.
+
 14.12.25 BJH  Release 10.69.00
 
               pnmnorm: add -bsingle, -wsingle.
diff --git a/lib/pmfileio.c b/lib/pmfileio.c
index b629fd23..a4533b56 100644
--- a/lib/pmfileio.c
+++ b/lib/pmfileio.c
@@ -306,17 +306,130 @@ pm_make_tmpfile(FILE **       const filePP,
 
 
 
+bool const canUnlinkOpen = 
+#if CAN_UNLINK_OPEN
+    1
+#else
+    0
+#endif
+    ;
+
+
+
+typedef struct UnlinkListEntry {
+/*----------------------------------------------------------------------------
+   This is an entry in the linked list of files to close and unlink as the
+   program exits.
+-----------------------------------------------------------------------------*/
+    struct UnlinkListEntry * next;
+    int                      fd;
+    char                     fileName[1];  /* Actually variable length */
+} UnlinkListEntry;
+
+static UnlinkListEntry * unlinkListP;
+
+
+
+static void
+unlinkTempFiles(void) {
+/*----------------------------------------------------------------------------
+  Close and unlink (so presumably delete) the files in the list
+  *unlinkListP.
+
+  This is an atexit function.
+-----------------------------------------------------------------------------*/
+    while (unlinkListP) {
+        UnlinkListEntry * const firstEntryP = unlinkListP;
+
+        unlinkListP = unlinkListP->next;
+
+        close(firstEntryP->fd);
+        unlink(firstEntryP->fileName);
+
+        free(firstEntryP);
+    }
+}
+
+
+
+static UnlinkListEntry *
+newUnlinkListEntry(const char * const fileName,
+                   int          const fd) {
+
+    UnlinkListEntry * const unlinkListEntryP =
+        malloc(sizeof(*unlinkListEntryP) + strlen(fileName) + 1);
+
+    if (unlinkListEntryP) {
+        strcpy(unlinkListEntryP->fileName, fileName);
+        unlinkListEntryP->fd   = fd;
+        unlinkListEntryP->next = NULL;
+    }
+    return unlinkListEntryP;
+}
+
+
+
+static void
+addUnlinkListEntry(const char * const fileName,
+                   int          const fd) {
+
+    UnlinkListEntry * const unlinkListEntryP =
+        newUnlinkListEntry(fileName, fd);
+
+    if (unlinkListEntryP) {
+        unlinkListEntryP->next = unlinkListP;
+        unlinkListP = unlinkListEntryP;
+    }
+}
+
+
+
+static void
+scheduleUnlinkAtExit(const char * const fileName,
+                     int          const fd) {
+/*----------------------------------------------------------------------------
+   Set things up to have the file unlinked as the program exits.
+
+   This is messy and probably doesn't work in all situations; it is a hack
+   to get Unix code essentially working on Windows, without messing up the
+   code too badly for Unix.
+-----------------------------------------------------------------------------*/
+    static bool unlinkListEstablished = false;
+    
+    if (!unlinkListEstablished) {
+        atexit(unlinkTempFiles);
+        unlinkListP = NULL;
+        unlinkListEstablished = true;
+    }
+
+    addUnlinkListEntry(fileName, fd);
+}
+
+
+
+static void
+arrangeUnlink(const char * const fileName,
+              int          const fd) {
+
+    if (canUnlinkOpen)
+        unlink(fileName);
+    else
+        scheduleUnlinkAtExit(fileName, fd);
+}
+
+
+
 FILE * 
 pm_tmpfile(void) {
 
     FILE * fileP;
-    const char * tmpfile;
+    const char * tmpfileNm;
 
-    pm_make_tmpfile(&fileP, &tmpfile);
+    pm_make_tmpfile(&fileP, &tmpfileNm);
 
-    unlink(tmpfile);
+    arrangeUnlink(tmpfileNm, fileno(fileP));
 
-    pm_strfree(tmpfile);
+    pm_strfree(tmpfileNm);
 
     return fileP;
 }
@@ -327,13 +440,13 @@ int
 pm_tmpfile_fd(void) {
 
     int fd;
-    const char * tmpfile;
+    const char * tmpfileNm;
 
-    pm_make_tmpfile_fd(&fd, &tmpfile);
+    pm_make_tmpfile_fd(&fd, &tmpfileNm);
 
-    unlink(tmpfile);
+    arrangeUnlink(tmpfileNm, fd);
 
-    pm_strfree(tmpfile);
+    pm_strfree(tmpfileNm);
 
     return fd;
 }
diff --git a/pm_config.in.h b/pm_config.in.h
index 1e54f06e..f88a7652 100644
--- a/pm_config.in.h
+++ b/pm_config.in.h
@@ -145,6 +145,15 @@
   #define HAVE_VASPRINTF 0
 #endif
 
+/* On Windows, unlinking a file is deleting it, and you can't delete an open
+   file, so unlink of an open file fails.  The errno is (incorrectly) EACCES.
+*/
+#if MSVCRT || defined(__CYGWIN__) || defined(DJGPP)
+  #define CAN_UNLINK_OPEN 0
+#else
+  #define CAN_UNLINK_OPEN 1
+#endif
+
 #ifdef __amigaos__
 #include <clib/exec_protos.h>
 #define getpid() ((pid_t)FindTask(NULL))