sed: fix 2 bugs (one testsuite entry + one newly found)

but more importantly make code more understandable


git-svn-id: svn://busybox.net/trunk/busybox@17632 69ca8d6d-28ef-0310-b511-8ec308f3f277

2 files changed, 63 insertions, 59 deletions

diff --git a/editors/sed.c b/editors/sed.c
index 28ee698e4..70be2e824 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -72,7 +72,7 @@ typedef struct sed_cmd_s {
         int beg_line;           /* 'sed 1p'   0 == apply commands to all lines */
         int end_line;           /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */
 
-        FILE *file;             /* File (sw) command writes to, -1 for none. */
+        FILE *sw_file;          /* File (sw) command writes to, -1 for none. */
         char *string;           /* Data string for (saicytb) commands. */
 
         unsigned short which_match;     /* (s) Which match to replace (0 for all) */
@@ -82,7 +82,7 @@ typedef struct sed_cmd_s {
         unsigned int in_match:1;        /* Next line also included in match? */
         unsigned int sub_p:1;           /* (s) print option */
 
-//      int sw_last_char;                  /* Last line written by (sw) had no '\n' */
+        char sw_last_char;                  /* Last line written by (sw) had no '\n' */
 
         /* GENERAL FIELDS */
         char cmd;               /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
@@ -130,8 +130,8 @@ static void sed_free_and_close_stuff(void)
         while (sed_cmd) {
                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 
-                if (sed_cmd->file)
-                        xprint_and_close_file(sed_cmd->file);
+                if (sed_cmd->sw_file)
+                        xprint_and_close_file(sed_cmd->sw_file);
 
                 if (sed_cmd->beg_match) {
                         regfree(sed_cmd->beg_match);
@@ -423,7 +423,7 @@ static char *parse_cmd_args(sed_cmd_t *sed_cmd, char *cmdstr)
                         bb_error_msg_and_die("command only uses one address");
                 cmdstr += parse_file_cmd(sed_cmd, cmdstr, &sed_cmd->string);
                 if (sed_cmd->cmd == 'w')
-                        sed_cmd->file = xfopen(sed_cmd->string, "w");
+                        sed_cmd->sw_file = xfopen(sed_cmd->string, "w");
         /* handle branch commands */
         } else if (strchr(":btT", sed_cmd->cmd)) {
                 int length;
@@ -717,21 +717,22 @@ static void add_input_file(FILE *file)
         bbg.input_file_list[bbg.input_file_count++] = file;
 }
 
-enum {
-        MASK_NO_EOL_CHAR = 0x100,
-        //MASK_FIRST_LINE = 0x200,
-};
-
 /* Get next line of input from bbg.input_file_list, flushing append buffer and
  * noting if we ran out of files without a newline on the last line we read.
  */
-static char *get_next_line(int *last_char)
+enum {
+        NO_EOL_CHAR = 1,
+};
+static char *get_next_line(char *gets_char)
 {
         char *temp = NULL;
-        int len, lc;
+        int len, gc;
 
-        lc = 0;
         flush_append();
+
+        /* will be returned if last line in the file
+         * doesn't end with either '\n' or '\0' */
+        gc = NO_EOL_CHAR;
         while (bbg.current_input_file < bbg.input_file_count) {
                 /* Read line up to a newline or NUL byte, inclusive,
                  * return malloc'ed char[]. length of the chunk read
@@ -743,26 +744,29 @@ static char *get_next_line(int *last_char)
                         char c = temp[len-1];
                         if (c == '\n' || c == '\0') {
                                 temp[len-1] = '\0';
-                                lc |= (unsigned char)c;
+                                gc = (unsigned char)c;
                                 break;
                         }
-                        /* will be returned if last line in the file
-                         * doesn't end with either '\n' or '\0' */
-                        lc |= MASK_NO_EOL_CHAR;
+                /* NB: I had the idea of peeking next file(s) and returning
+                 * NO_EOL_CHAR only if it is the *last* non-empty
+                 * input file. But there is a case where this won't work:
+                 * file1: "a woo\nb woo"
+                 * file2: "c no\nd no"
+                 * sed -ne 's/woo/bang/p' input1 input2 => "a bang\nb bang"
+                 * (note: *no* newline after "b bang"!) */
+
                         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 |= MASK_FIRST_LINE;
         }
-        *last_char = lc;
+        *gets_char = gc;
         return temp;
 }
 
 /* Output line of text. */
 /* Note:
- * The tricks with MASK_FIRST_LINE and last_puts_char are there to emulate gnu sed.
+ * The tricks with NO_EOL_CHAR and last_puts_char are there to emulate gnu sed.
  * Without them, we had this:
  * echo -n thingy >z1
  * echo -n again >z2
@@ -774,37 +778,32 @@ static char *get_next_line(int *last_char)
  * bbox:
  * 00000000  74 68 7a 6e 67 79 61 67  61 7a 6e                 |thzngyagazn|
  */
-static void puts_maybe_newline(char *s, FILE *file, int last_char)
+static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char last_gets_char)
 {
-        static char last_puts_char = '\n';
+        char lpc = *last_puts_char;
 
         /* Is this a first line from new file
          * and old file didn't end with '\n' or '\0'? */
-//      if ((last_char & MASK_FIRST_LINE) && last_puts_char != '\n') {
-        if (last_puts_char != '\n' && last_puts_char != '\0') {
+        if (lpc != '\n' && lpc != '\0') {
                 fputc('\n', file);
-                last_puts_char = '\n';
+                lpc = '\n';
         }
         fputs(s, file);
-        /* why 'x'? - just something which is not '\n' */
+        /* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */
         if (s[0])
-                last_puts_char = 'x';
-        if (!(last_char & MASK_NO_EOL_CHAR)) { /* had trailing '\n' or '\0'? */
-                last_char &= 0xff;
-                fputc(last_char, file);
-                last_puts_char = last_char;
+                lpc = 'x';
+        if (last_gets_char != NO_EOL_CHAR) { /* had trailing '\n' or '\0'? */
+                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);
         }
-
-        /* Seems to be unused */
-        /*return last_char;*/
+        *last_puts_char = lpc;
 }
 
-#define sed_puts(s, n) (puts_maybe_newline(s, bbg.nonstdout, n))
+#define sed_puts(s, n) (puts_maybe_newline(s, bbg.nonstdout, &last_puts_char, n))
 
 /* Process all the lines in all the files */
 
@@ -812,12 +811,13 @@ static void process_files(void)
 {
         char *pattern_space, *next_line;
         int linenum = 0;
-        int last_char, next_last_char = 0;
+        char last_puts_char = '\n';
+        char last_gets_char, next_gets_char;
         sed_cmd_t *sed_cmd;
         int substituted;
 
         /* Prime the pump */
-        next_line = get_next_line(&next_last_char);
+        next_line = get_next_line(&next_gets_char);
 
         /* go through every line in each file */
 again:
@@ -826,11 +826,11 @@ again:
         /* Advance to next line.  Stop if out of lines. */
         pattern_space = next_line;
         if (!pattern_space) return;
-        last_char = next_last_char;
+        last_gets_char = next_gets_char;
 
         /* Read one line in advance so we can act on the last line,
          * the '$' address */
-        next_line = get_next_line(&next_last_char);
+        next_line = get_next_line(&next_gets_char);
         linenum++;
 restart:
         /* for every line, go through all the commands */
@@ -924,7 +924,7 @@ restart:
                                  * (of current file) is printed. Even if
                                  * that line is nonterminated, we print
                                  * '\n' here (gnu sed does the same) */
-                                sed_puts(pattern_space, (last_char & 0x200) | '\n');
+                                sed_puts(pattern_space, '\n');
                                 break;
                         /* Delete up through first newline */
                         case 'D':
@@ -950,12 +950,12 @@ restart:
 
                                 /* handle p option */
                                 if (sed_cmd->sub_p)
-                                        sed_puts(pattern_space, last_char);
+                                        sed_puts(pattern_space, last_gets_char);
                                 /* handle w option */
-                                if (sed_cmd->file)
-                                        /*sed_cmd->sw_last_char =*/ puts_maybe_newline(
-                                                pattern_space, sed_cmd->file,
-                                                last_char);
+                                if (sed_cmd->sw_file)
+                                        puts_maybe_newline(
+                                                pattern_space, sed_cmd->sw_file,
+                                                &sed_cmd->sw_last_char, last_gets_char);
                                 break;
 
                         /* Append line to linked list to be printed later */
@@ -972,7 +972,7 @@ restart:
                         case 'c':
                                 /* Only triggers on last line of a matching range. */
                                 if (!sed_cmd->in_match)
-                                        sed_puts(sed_cmd->string, MASK_NO_EOL_CHAR);
+                                        sed_puts(sed_cmd->string, NO_EOL_CHAR);
                                 goto discard_line;
 
                         /* Read file, append contents to output */
@@ -995,20 +995,20 @@ restart:
 
                         /* Write pattern space to file. */
                         case 'w':
-                                /*sed_cmd->sw_last_char =*/ puts_maybe_newline(
-                                        pattern_space, sed_cmd->file,
-                                        last_char);
+                                puts_maybe_newline(
+                                        pattern_space, sed_cmd->sw_file,
+                                        &sed_cmd->sw_last_char, last_gets_char);
                                 break;
 
                         /* Read next line from input */
                         case 'n':
                                 if (!bbg.be_quiet)
-                                        sed_puts(pattern_space, last_char);
+                                        sed_puts(pattern_space, last_gets_char);
                                 if (next_line) {
                                         free(pattern_space);
                                         pattern_space = next_line;
-                                        last_char = next_last_char;
-                                        next_line = get_next_line(&next_last_char);
+                                        last_gets_char = next_gets_char;
+                                        next_line = get_next_line(&next_gets_char);
                                         linenum++;
                                         break;
                                 }
@@ -1037,8 +1037,8 @@ restart:
                                 pattern_space = realloc(pattern_space, len + strlen(next_line) + 2);
                                 pattern_space[len] = '\n';
                                 strcpy(pattern_space + len+1, next_line);
-                                last_char = next_last_char;
-                                next_line = get_next_line(&next_last_char);
+                                last_gets_char = next_gets_char;
+                                next_line = get_next_line(&next_gets_char);
                                 linenum++;
                                 break;
                         }
@@ -1093,7 +1093,7 @@ restart:
                                 strcat(pattern_space, "\n");
                                 if (bbg.hold_space)
                                         strcat(pattern_space, bbg.hold_space);
-                                last_char = '\n';
+                                last_gets_char = '\n';
 
                                 break;
                         }
@@ -1125,7 +1125,7 @@ restart:
                         {
                                 char *tmp = pattern_space;
                                 pattern_space = bbg.hold_space ? : xzalloc(1);
-                                last_char = '\n';
+                                last_gets_char = '\n';
                                 bbg.hold_space = tmp;
                                 break;
                         }
@@ -1140,7 +1140,7 @@ restart:
         /* we will print the line unless we were told to be quiet ('-n')
            or if the line was suppressed (ala 'd'elete) */
         if (!bbg.be_quiet)
-                sed_puts(pattern_space, last_char);
+                sed_puts(pattern_space, last_gets_char);
 
         /* Delete and such jump here. */
  discard_line:
diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index a386f1723..cc200703d 100755
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -139,6 +139,10 @@ testing "sed selective matches noinsert newline" \
 testing "sed clusternewline" \
         "sed -e '/one/a 111' -e '/two/i 222' -e p input -" \
         "one\none\n111\n222\ntwo\ntwo" "one" "two"
+testing "sed subst+write" \
+        "sed -e 's/i/z/' -e 'woutputw' input -; echo -n X; cat outputw" \
+        "thzngy\nagaznXthzngy\nagazn" "thingy" "again"
+rm outputw
 
 # Test end-of-file matching behavior