Make the code a bit more like the pre-new-APIs code.

Change-Id: I40282d8825936d24480c9b77e2e7d9374b1de6b5
Reviewed-on: https://code.wireshark.org/review/4534
Reviewed-by: Guy Harris <guy@alum.mit.edu>

8 files changed, 50 insertions, 108 deletions

diff --git a/wiretap/k12.c b/wiretap/k12.c
index f9b1c3ed80..6dd95e680b 100644
--- a/wiretap/k12.c
+++ b/wiretap/k12.c
@@ -854,8 +854,9 @@ int k12_open(wtap *wth, int *err, gchar **err_info) {
 
     if ( !wtap_read_bytes(wth->fh,header_buffer,K12_FILE_HDR_LEN,err,err_info) ) {
         K12_DBG(1,("k12_open: FILE HEADER TOO SHORT OR READ ERROR"));
-        if (*err != WTAP_ERR_SHORT_READ)
+        if (*err != WTAP_ERR_SHORT_READ) {
             return -1;
+        }
         return 0;
     }
 
diff --git a/wiretap/lanalyzer.c b/wiretap/lanalyzer.c
index 7fdbd4610f..70b0403cdd 100644
--- a/wiretap/lanalyzer.c
+++ b/wiretap/lanalyzer.c
@@ -313,14 +313,9 @@ int lanalyzer_open(wtap *wth, int *err, gchar **err_info)
 	}
 	if (!wtap_read_bytes(wth->fh, &header_fixed, sizeof header_fixed,
 	    err, err_info)) {
-		if (*err == WTAP_ERR_SHORT_READ) {
-			/*
-			 * Not enough bytes for the fixed-length part of
-			 * the header, so not a LANAlyzer file.
-			 */
-			return 0;
-		}
-		return -1;
+		if (*err != WTAP_ERR_SHORT_READ)
+			return -1;
+		return 0;
 	}
 	record_length -= sizeof header_fixed;
 
@@ -329,14 +324,9 @@ int lanalyzer_open(wtap *wth, int *err, gchar **err_info)
 		comment = (char *)g_malloc(record_length + 1);
 		if (!wtap_read_bytes(wth->fh, comment, record_length,
 		    err, err_info)) {
-			if (*err == WTAP_ERR_SHORT_READ) {
-				/*
-				 * Not enough bytes for the rest of the
-				 * record, so not a LANAlyzer file.
-				 */
-				return 0;
-			}
-			return -1;
+			if (*err != WTAP_ERR_SHORT_READ)
+				return -1;
+			return 0;
 		}
 		comment[record_length] = '\0';
 		wth->shb_hdr.opt_comment = comment;
diff --git a/wiretap/logcat.c b/wiretap/logcat.c
index 26d7a0b2ce..63eea918a7 100644
--- a/wiretap/logcat.c
+++ b/wiretap/logcat.c
@@ -70,13 +70,9 @@ static gint detect_version(FILE_T fh, int *err, gchar **err_info)
              */
             return -2;
         }
-        if (*err == WTAP_ERR_SHORT_READ) {
-            /*
-             * Not enough bytes for a packet, so not a logcat file.
-             */
-            return 0;
-        }
-        return -1;
+        if (*err != WTAP_ERR_SHORT_READ)
+            return -1;
+        return 0;
     }
     payload_length = pletoh16(&tmp);
 
@@ -89,13 +85,9 @@ static gint detect_version(FILE_T fh, int *err, gchar **err_info)
 
     /* 16-bit header length (or padding, equal to 0x0000) */
     if (!wtap_read_bytes(fh, &tmp, 2, err, err_info)) {
-        if (*err == WTAP_ERR_SHORT_READ) {
-            /*
-             * Not enough bytes for a packet, so not a logcat file.
-             */
-            return 0;
-        }
-        return -1;
+        if (*err != WTAP_ERR_SHORT_READ)
+            return -1;
+        return 0;
     }
     hdr_size = pletoh16(&tmp);
     read_sofar = 4;
@@ -121,13 +113,9 @@ static gint detect_version(FILE_T fh, int *err, gchar **err_info)
 
         if (!wtap_read_bytes(fh, buffer + read_sofar, entry_len - read_sofar, err, err_info)) {
             g_free(buffer);
-            if (*err == WTAP_ERR_SHORT_READ) {
-                /*
-                 * Not enough bytes for a packet, so not a logcat file.
-                 */
-                return 0;
-            }
-            return -1;
+            if (*err != WTAP_ERR_SHORT_READ)
+                return -1;
+            return 0;
         }
         read_sofar += entry_len - read_sofar;
 
diff --git a/wiretap/network_instruments.c b/wiretap/network_instruments.c
index 1235cd8dd9..555414253c 100644
--- a/wiretap/network_instruments.c
+++ b/wiretap/network_instruments.c
@@ -103,9 +103,8 @@ static int read_packet_header(FILE_T fh, union wtap_pseudo_header *pseudo_header
 static gboolean process_packet_header(wtap *wth,
     packet_entry_header *packet_header, struct wtap_pkthdr *phdr, int *err,
     gchar **err_info);
-static int read_packet_data(FILE_T fh, int offset_to_frame,
-    int current_offset_from_packet_header, Buffer *buf, int length,
-    int *err, char **err_info);
+static int read_packet_data(FILE_T fh, int offset_to_frame, int current_offset_from_packet_header,
+    Buffer *buf, int length, int *err, char **err_info);
 static gboolean skip_to_next_packet(wtap *wth, int offset_to_next_packet,
     int current_offset_from_packet_header, int *err, char **err_info);
 static gboolean observer_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
@@ -338,9 +337,9 @@ read_packet_header(FILE_T fh, union wtap_pseudo_header *pseudo_header,
     /* pull off the packet header */
     if (!wtap_read_bytes_or_eof(fh, packet_header, sizeof *packet_header,
                                 err, err_info)) {
-        if (*err == 0)
-            return 0;    /* EOF */
-        return -1;
+        if (*err != 0)
+            return -1;
+        return 0;    /* EOF */
     }
     offset += (int)sizeof *packet_header;
     PACKET_ENTRY_HEADER_FROM_LE_IN_PLACE(*packet_header);
@@ -498,9 +497,8 @@ process_packet_header(wtap *wth, packet_entry_header *packet_header,
 }
 
 static int
-read_packet_data(FILE_T fh, int offset_to_frame,
-    int current_offset_from_packet_header, Buffer *buf, int length,
-    int *err, char **err_info)
+read_packet_data(FILE_T fh, int offset_to_frame, int current_offset_from_packet_header, Buffer *buf,
+    int length, int *err, char **err_info)
 {
     int seek_increment;
     int bytes_consumed = 0;
@@ -534,8 +532,8 @@ read_packet_data(FILE_T fh, int offset_to_frame,
 }
 
 static gboolean
-skip_to_next_packet(wtap *wth, int offset_to_next_packet,
-    int current_offset_from_packet_header, int *err, char **err_info)
+skip_to_next_packet(wtap *wth, int offset_to_next_packet, int current_offset_from_packet_header, int *err,
+    char **err_info)
 {
     int seek_increment;
 
diff --git a/wiretap/ngsniffer.c b/wiretap/ngsniffer.c
index 9bc8f62c2d..b29840bbfc 100644
--- a/wiretap/ngsniffer.c
+++ b/wiretap/ngsniffer.c
@@ -790,9 +790,9 @@ process_header_records(wtap *wth, int *err, gchar **err_info, gint16 maj_vers,
 	for (;;) {
 		errno = WTAP_ERR_CANT_READ;
 		if (!wtap_read_bytes_or_eof(wth->fh, record_type, 2, err, err_info)) {
-			if (*err == 0)
-				return 0;	/* EOF */
-			return -1;
+			if (*err != 0)
+				return -1;
+			return 0;	/* EOF */
 		}
 
 		type = pletoh16(record_type);
diff --git a/wiretap/packetlogger.c b/wiretap/packetlogger.c
index 8526cddada..c8235fd5f8 100644
--- a/wiretap/packetlogger.c
+++ b/wiretap/packetlogger.c
@@ -67,14 +67,9 @@ int packetlogger_open(wtap *wth, int *err, gchar **err_info)
 	}
 
 	if (!wtap_read_bytes(wth->fh, &type, 1, err, err_info)) {
-		if (*err == WTAP_ERR_SHORT_READ) {
-			/*
-			 * Not enough bytes for the packet, so not a
-			 * packetlogger file.
-			 */
-			return 0;
-		}
-		return -1;
+		if (*err != WTAP_ERR_SHORT_READ)
+			return -1;
+		return 0;
 	}
 
 	/* Verify this file belongs to us */
diff --git a/wiretap/peekclassic.c b/wiretap/peekclassic.c
index f1e109bbe1..cfd4c91bef 100644
--- a/wiretap/peekclassic.c
+++ b/wiretap/peekclassic.c
@@ -199,14 +199,9 @@ int peekclassic_open(wtap *wth, int *err, gchar **err_info)
 		        PEEKCLASSIC_V567_HDR_SIZE);
 		if (!wtap_read_bytes(wth->fh, &ep_hdr.secondary.v567,
 		    (int)sizeof(ep_hdr.secondary.v567), err, err_info)) {
-			if (*err == WTAP_ERR_SHORT_READ) {
-				/*
-				 * Not enough bytes for a secondary
-				 * header, so not a Peek classic file.
-				 */
-				return 0;
-			}
-			return -1;
+			if (*err != WTAP_ERR_SHORT_READ)
+				return -1;
+			return 0;
 		}
 
 		if ((0 != ep_hdr.secondary.v567.reserved[0]) ||
diff --git a/wiretap/radcom.c b/wiretap/radcom.c
index bc19af68b4..188882fd24 100644
--- a/wiretap/radcom.c
+++ b/wiretap/radcom.c
@@ -122,14 +122,9 @@ int radcom_open(wtap *wth, int *err, gchar **err_info)
 	 * be located 32 bytes before the beginning of this string */
 	errno = WTAP_ERR_CANT_READ;
 	if (!wtap_read_bytes(wth->fh, t_magic, 11, err, err_info)) {
-		if (*err == WTAP_ERR_SHORT_READ) {
-			/*
-			 * Not enough bytes for the active time string,
-			 * so not a RADCOM file.
-			 */
-			return 0;
-		}
-		return -1;
+		if (*err != WTAP_ERR_SHORT_READ)
+			return -1;
+		return 0;
 	}
 	while (memcmp(t_magic, active_time_magic, 11) != 0)
 	{
@@ -137,14 +132,9 @@ int radcom_open(wtap *wth, int *err, gchar **err_info)
 			return -1;
 		errno = WTAP_ERR_CANT_READ;
 		if (!wtap_read_bytes(wth->fh, t_magic, 11, err, err_info)) {
-			if (*err == WTAP_ERR_SHORT_READ) {
-				/*
-				 * Not enough bytes for the active time string,
-				 * so not a RADCOM file.
-				 */
-				return 0;
-			}
-			return -1;
+			if (*err != WTAP_ERR_SHORT_READ)
+				return -1;
+			return 0;
 		}
 	}
 	if (file_seek(wth->fh, -43, SEEK_CUR, err) == -1) return -1;
@@ -153,14 +143,9 @@ int radcom_open(wtap *wth, int *err, gchar **err_info)
 	errno = WTAP_ERR_CANT_READ;
 	if (!wtap_read_bytes(wth->fh, &start_date, sizeof(struct frame_date),
 	    err, err_info)) {
-		if (*err == WTAP_ERR_SHORT_READ) {
-			/*
-			 * Not enough bytes for the start time, so not
-			 * a RADCOM file.
-			 */
-			return 0;
-		}
-		return -1;
+		if (*err != WTAP_ERR_SHORT_READ)
+			return -1;
+		return 0;
 	}
 
 	if (file_seek(wth->fh, sizeof(struct frame_date), SEEK_CUR, err) == -1)
@@ -170,14 +155,9 @@ int radcom_open(wtap *wth, int *err, gchar **err_info)
 		errno = WTAP_ERR_CANT_READ;
 		if (!wtap_read_bytes(wth->fh, search_encap, 4,
 		    err, err_info)) {
-			if (*err == WTAP_ERR_SHORT_READ) {
-				/*
-				 * Not enough bytes for the encapsulation,
-				 * so not a RADCOM file.
-				 */
-				return 0;
-			}
-			return -1;
+			if (*err != WTAP_ERR_SHORT_READ)
+				return -1;
+			return 0;
 		}
 
 		if (memcmp(encap_magic, search_encap, 4) == 0)
@@ -196,14 +176,9 @@ int radcom_open(wtap *wth, int *err, gchar **err_info)
 		return -1;
 	errno = WTAP_ERR_CANT_READ;
 	if (!wtap_read_bytes(wth->fh, search_encap, 4, err, err_info)) {
-		if (*err == WTAP_ERR_SHORT_READ) {
-			/*
-			 * Not enough bytes for the start time, so not
-			 * a RADCOM file.
-			 */
-			return 0;
-		}
-		return -1;
+		if (*err != WTAP_ERR_SHORT_READ)
+			return -1;
+		return 0;
 	}
 
 	/* This is a radcom file */