sed: fix handling of files not ending in '\n'

1 files changed, 30 insertions, 10 deletions

diff --git a/editors/sed.c b/editors/sed.c
index 630d6d792..94368aa68 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -81,6 +81,7 @@ typedef struct sed_cmd_s {
         unsigned int invert:1;          /* the '!' after the address */
         unsigned int in_match:1;        /* Next line also included in match? */
         unsigned int sub_p:1;           /* (s) print option */
+
         int last_char;                  /* Last line written by (sw) had no '\n' */
 
         /* GENERAL FIELDS */
@@ -715,12 +716,9 @@ static void add_input_file(FILE *file)
 static char *get_next_line(int *last_char)
 {
         char *temp = NULL;
-        int len;
-
-        /* will be returned if last line in the file
-         * doesn't end with either '\n' or '\0' */
-        *last_char = 0x100;
+        int len, lc;
 
+        lc = 0;
         flush_append();
         while (bbg.current_input_file < bbg.input_file_count) {
                 temp = bb_get_chunk_from_file(
@@ -730,18 +728,27 @@ static char *get_next_line(int *last_char)
                         char c = temp[len-1];
                         if (c == '\n' || c == '\0') {
                                 temp[len-1] = '\0';
-                                *last_char = (unsigned char)c;
+                                lc |= (unsigned char)c;
+                                break;
                         }
+                        /* will be returned if last line in the file
+                         * doesn't end with either '\n' or '\0' */
+                        lc |= 0x100;
                         break;
                 }
                 /* Close this file and advance to next one */
                 fclose(bbg.input_file_list[bbg.current_input_file++]);
+                /* "this is the first line from new input file" */
+                lc |= 0x200;
         }
+        *last_char = lc;
         return temp;
 }
 
 /* Output line of text. */
 /* Note:
+ * The tricks with 0x200 and last_puts_char are there to emulate gnu sed.
+ * Without them, we had this:
  * echo -n thingy >z1
  * echo -n again >z2
  * >znull
@@ -750,13 +757,26 @@ static char *get_next_line(int *last_char)
  * 00000000  74 68 7a 6e 67 79 0a 61  67 61 7a 6e              |thzngy.agazn|
  * bbox:
  * 00000000  74 68 7a 6e 67 79 61 67  61 7a 6e                 |thzngyagazn|
- * I am not sure that bbox is wrong here...
  */
 
 static int puts_maybe_newline(char *s, FILE *file, int prev_last_char, int last_char)
 {
+        static char last_puts_char;
+
+        /* Is this a first line from new file
+         * and old file didn't end with '\n'? */
+        if ((last_char & 0x200) && last_puts_char != '\n') {
+                fputc('\n', file);
+                last_puts_char = '\n';
+        }
         fputs(s, file);
-        if (last_char < 0x100) fputc(last_char, file);
+        /* 'x': we don't care what is it, but we know it isn't '\n' */
+        if (s[0]) last_puts_char = 'x';
+        if (!(last_char & 0x100)) { /* had trailing '\n' or '\0'? */
+                last_char &= 0xff;
+                fputc(last_char, file);
+                last_puts_char = last_char;
+        }
 
         if (ferror(file)) {
                 xfunc_error_retval = 4;  /* It's what gnu sed exits with... */
@@ -1047,7 +1067,7 @@ restart:
                                         strcat(pattern_space, "\n");
                                         if (bbg.hold_space)
                                                 strcat(pattern_space, bbg.hold_space);
-                                        last_char = 0x100;
+                                        last_char = '\n';
 
                                         break;
                                 }
@@ -1079,7 +1099,7 @@ restart:
                                 {
                                         char *tmp = pattern_space;
                                         pattern_space = bbg.hold_space ? : xzalloc(1);
-                                        last_char = 0x100;
+                                        last_char = '\n';
                                         bbg.hold_space = tmp;
                                         break;
                                 }