add to testsuite and fix yet another sed corner case

2 files changed, 27 insertions, 6 deletions

diff --git a/editors/sed.c b/editors/sed.c
index bf40877e4..695e5e974 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -724,6 +724,7 @@ static void add_input_file(FILE *file)
  */
 enum {
         NO_EOL_CHAR = 1,
+        LAST_IS_NUL = 2,
 };
 static char *get_next_line(char *gets_char)
 {
@@ -737,17 +738,24 @@ static char *get_next_line(char *gets_char)
          * doesn't end with either '\n' or '\0' */
         gc = NO_EOL_CHAR;
         while (bbg.current_input_file < bbg.input_file_count) {
+                FILE *fp = bbg.input_file_list[bbg.current_input_file];
                 /* Read line up to a newline or NUL byte, inclusive,
                  * return malloc'ed char[]. length of the chunk read
                  * is stored in len. NULL if EOF/error */
-                temp = bb_get_chunk_from_file(
-                        bbg.input_file_list[bbg.current_input_file], &len);
+                temp = bb_get_chunk_from_file(fp, &len);
                 if (temp) {
                         /* len > 0 here, it's ok to do temp[len-1] */
                         char c = temp[len-1];
                         if (c == '\n' || c == '\0') {
                                 temp[len-1] = '\0';
                                 gc = c;
+                                if (c == '\0') {
+                                        int ch = fgetc(fp);
+                                        if (ch != EOF)
+                                                ungetc(ch, fp);
+                                        else
+                                                gc = LAST_IS_NUL;
+                                }
                         }
                         /* else we put NO_EOL_CHAR into *gets_char */
                         break;
@@ -761,7 +769,8 @@ static char *get_next_line(char *gets_char)
                  * (note: *no* newline after "b bang"!) */
                 }
                 /* Close this file and advance to next one */
-                fclose(bbg.input_file_list[bbg.current_input_file++]);
+                fclose(fp);
+                bbg.current_input_file++;
         }
         *gets_char = gc;
         return temp;
@@ -785,20 +794,29 @@ static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char l
 {
         char lpc = *last_puts_char;
 
-        /* Is this a first line from new file
-         * and old file didn't end with '\n' or '\0'? */
+        /* Need to insert a '\n' between two files because first file's
+         * last line wasn't terminated? */
         if (lpc != '\n' && lpc != '\0') {
                 fputc('\n', file);
                 lpc = '\n';
         }
         fputs(s, file);
+
         /* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */
         if (s[0])
                 lpc = 'x';
-        if (last_gets_char != NO_EOL_CHAR) { /* had trailing '\n' or '\0'? */
+
+        /* had trailing '\0' and it was last char of file? */
+        if (last_gets_char == LAST_IS_NUL) {
+                fputc('\0', file);
+                lpc = 'x'; /* */
+        } else
+        /* had trailing '\n' or '\0'? */
+        if (last_gets_char != NO_EOL_CHAR) {
                 fputc(last_gets_char, file);
                 lpc = last_gets_char;
         }
+
         if (ferror(file)) {
                 xfunc_error_retval = 4;  /* It's what gnu sed exits with... */
                 bb_error_msg_and_die(bb_msg_write_error);
diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index cc200703d..9576b6c4b 100755
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -143,6 +143,9 @@ testing "sed subst+write" \
         "sed -e 's/i/z/' -e 'woutputw' input -; echo -n X; cat outputw" \
         "thzngy\nagaznXthzngy\nagazn" "thingy" "again"
 rm outputw
+testing "sed trailing NUL" \
+        "sed 's/i/z/' input -" \
+        "a\0b\0\nc" "a\0b\0" "c"
 
 # Test end-of-file matching behavior