From: David Levine <levinedl@acm.org>
Date: Tue, 29 Jan 2013 03:20:22 +0000 (-0600)
Subject: Added m_getfld_track_filepos() for callers to indicate that they
X-Git-Url: https://diplodocus.org/git/nmh/commitdiff_plain/f52aa1ce52a53ead867f840f18c834871925de6c?ds=inline;hp=--cc

Added m_getfld_track_filepos() for callers to indicate that they
may interleave fseek*/ftell* calls with m_getfld() calls.  This
eliminates the need for m_getfld() to call fseek() when called
by inc(1) and scan(1).
---

f52aa1ce52a53ead867f840f18c834871925de6c
diff --git a/h/prototypes.h b/h/prototypes.h
index 53e8b25d..6db8e169 100644
--- a/h/prototypes.h
+++ b/h/prototypes.h
@@ -79,6 +79,7 @@ char *m_draft (char *, char *, int, int *);
 void m_eomsbr (m_getfld_state_t, int (*)(int));
 void m_getfld_state_reset (m_getfld_state_t *);
 void m_getfld_state_destroy (m_getfld_state_t *);
+void m_getfld_track_filepos (m_getfld_state_t *, FILE *);
 int m_getfld (m_getfld_state_t *, unsigned char[NAMESZ], unsigned char *, int *, FILE *);
 int m_gmprot (void);
 char *m_maildir (char *);
diff --git a/sbr/m_getfld.c b/sbr/m_getfld.c
index 4a512269..e7379dfe 100644
--- a/sbr/m_getfld.c
+++ b/sbr/m_getfld.c
@@ -266,6 +266,7 @@ struct m_getfld_state {
     int edelimlen;
     int (*eom_action)(int);
     int state;
+    int track_filepos;
 };
 
 static
@@ -285,6 +286,7 @@ m_getfld_state_init (m_getfld_state_t *gstate, FILE *iob) {
     s->fdelimlen = s->edelimlen = 0;
     s->eom_action = NULL;
     s->state = FLD;
+    s->track_filepos = 0;
 }
 
 /* scan() needs to force a state an initial state of FLD for each message. */
@@ -295,6 +297,18 @@ m_getfld_state_reset (m_getfld_state_t *gstate) {
     }
 }
 
+/* If the caller interleaves ftell*()/fseek*() calls with m_getfld()
+   calls, m_getfld() must keep track of the file position.  The caller
+   must use this function to inform m_getfld(). */
+void
+m_getfld_track_filepos (m_getfld_state_t *gstate, FILE *iob) {
+    if (! *gstate) {
+	m_getfld_state_init (gstate, iob);
+    }
+
+    (*gstate)->track_filepos = 1;
+}
+
 void m_getfld_state_destroy (m_getfld_state_t *gstate) {
     m_getfld_state_t s = *gstate;
 
@@ -353,7 +367,7 @@ enter_getfld (m_getfld_state_t *gstate, FILE *iob) {
        readpos shift code being currently unused. */
     s->iob = iob;
 
-    if (pos != 0  ||  s->last_internal_pos != 0) {
+    if (s->track_filepos  &&  (pos != 0  ||  s->last_internal_pos != 0)) {
 	if (s->last_internal_pos == 0) {
 	    s->total_bytes_read = pos;
 	} else {
@@ -397,13 +411,16 @@ enter_getfld (m_getfld_state_t *gstate, FILE *iob) {
 
 static void
 leave_getfld (m_getfld_state_t s) {
-    /* Save the internal file position that we use for the input buffer. */
-    s->last_internal_pos = ftello (s->iob);
-
-    /* Set file stream position so that callers can use ftell(). */
     s->total_bytes_read += s->bytes_read;
-    fseeko (s->iob, s->total_bytes_read, SEEK_SET);
-    s->last_caller_pos = ftello (s->iob);
+
+    if (s->track_filepos) {
+	/* Save the internal file position that we use for the input buffer. */
+	s->last_internal_pos = ftello (s->iob);
+
+	/* Set file stream position so that callers can use ftell(). */
+	fseeko (s->iob, s->total_bytes_read, SEEK_SET);
+	s->last_caller_pos = ftello (s->iob);
+    }
 }
 
 static size_t
diff --git a/uip/mhbuildsbr.c b/uip/mhbuildsbr.c
index 7d187b39..a344a7c7 100644
--- a/uip/mhbuildsbr.c
+++ b/uip/mhbuildsbr.c
@@ -162,6 +162,7 @@ build_mime (char *infile, int directives)
      * draft into the linked list of header fields for
      * the new MIME message.
      */
+    m_getfld_track_filepos (&gstate, in);
     for (compnum = 1;;) {
 	int bufsz = sizeof buf;
 	switch (state = m_getfld (&gstate, name, buf, &bufsz, in)) {
diff --git a/uip/mhparse.c b/uip/mhparse.c
index d4c6f10a..0dcd1333 100644
--- a/uip/mhparse.c
+++ b/uip/mhparse.c
@@ -276,6 +276,7 @@ get_content (FILE *in, char *file, int toplevel)
      * Parse the header fields for this
      * content into a linked list.
      */
+    m_getfld_track_filepos (&gstate, in);
     for (compnum = 1;;) {
 	int bufsz = sizeof buf;
 	switch (state = m_getfld (&gstate, name, buf, &bufsz, in)) {
diff --git a/uip/sendsbr.c b/uip/sendsbr.c
index 4c447414..06358fd3 100644
--- a/uip/sendsbr.c
+++ b/uip/sendsbr.c
@@ -603,6 +603,7 @@ splitmsg (char **vec, int vecp, char *drft, struct stat *st, int delay)
      * Scan through the message and examine the various header fields,
      * as well as locate the beginning of the message body.
      */
+    m_getfld_track_filepos (&gstate, in);
     for (compnum = 1;;) {
 	int bufsz = sizeof buffer;
 	switch (state = m_getfld (&gstate, name, buffer, &bufsz, in)) {