21f6fbf54
Denys Vlasenko
2012-06-04
Subject
sed: fix zero chars match/replace
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editors/sed.c+42 -22
| @@ -673,7 +673,7 @@ static void do_subst_w_backrefs(char *line, char *replace) | |
| /* go through the replacement string */ | |
| for (i = 0; replace[i]; i++) { | |
| - | /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */ |
| + | /* if we find a backreference (\1, \2, etc.) print the backref'ed text */ |
| if (replace[i] == '\\') { | |
| unsigned backref = replace[++i] - '0'; | |
| if (backref <= 9) { | |
| @@ -707,8 +707,10 @@ static void do_subst_w_backrefs(char *line, char *replace) | |
| static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p) | |
| { | |
| char *line = *line_p; | |
| - | int altered = 0; |
| unsigned match_count = 0; | |
| + | bool altered = 0; |
| + | bool prev_match_empty = 1; |
| + | bool tried_at_eol = 0; |
| regex_t *current_regex; | |
| current_regex = sed_cmd->sub_match; | |
| @@ -737,46 +739,64 @@ static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p) | |
| do { | |
| int i; | |
| - | /* Work around bug in glibc regexec, demonstrated by: |
| - | * echo " a.b" | busybox sed 's [^ .]* x g' |
| - | * The match_count check is so not to break |
| - | * echo "hi" | busybox sed 's/^/!/g' |
| - | */ |
| - | if (!G.regmatch[0].rm_so && !G.regmatch[0].rm_eo && match_count) { |
| - | pipe_putc(*line++); |
| - | goto next; |
| - | } |
| - | |
| match_count++; | |
| /* If we aren't interested in this match, output old line to | |
| - | end of match and continue */ |
| + | * end of match and continue */ |
| if (sed_cmd->which_match | |
| && (sed_cmd->which_match != match_count) | |
| ) { | |
| for (i = 0; i < G.regmatch[0].rm_eo; i++) | |
| pipe_putc(*line++); | |
| + | /* Null match? Print one more char */ |
| + | if (G.regmatch[0].rm_so == i && *line) |
| + | pipe_putc(*line++); |
| goto next; | |
| } | |
| - | /* print everything before the match */ |
| + | /* Print everything before the match */ |
| for (i = 0; i < G.regmatch[0].rm_so; i++) | |
| pipe_putc(line[i]); | |
| - | /* then print the substitution string */ |
| - | do_subst_w_backrefs(line, sed_cmd->string); |
| + | /* Then print the substitution string, |
| + | * unless we just matched empty string after non-empty one. |
| + | * Example: string "cccd", pattern "c*", repl "R": |
| + | * result is "RdR", not "RRdR": first match "ccc", |
| + | * second is "" before "d", third is "" after "d". |
| + | * Second match is NOT replaced! |
| + | */ |
| + | if (prev_match_empty || i != 0) { |
| + | dbg("inserting replacement at %d in '%s'", i, line); |
| + | do_subst_w_backrefs(line, sed_cmd->string); |
| + | } else { |
| + | dbg("NOT inserting replacement at %d in '%s'", i, line); |
| + | } |
| + | |
| + | /* If matched string is empty (f.e. "c*" pattern), |
| + | * copy verbatim one char after it before attempting more matches |
| + | */ |
| + | prev_match_empty = (G.regmatch[0].rm_eo == i); |
| + | if (prev_match_empty && line[i]) { |
| + | pipe_putc(line[i]); |
| + | G.regmatch[0].rm_eo++; |
| + | } |
| - | /* advance past the match */ |
| + | /* Advance past the match */ |
| + | dbg("line += %d", G.regmatch[0].rm_eo); |
| line += G.regmatch[0].rm_eo; | |
| - | /* flag that something has changed */ |
| - | altered++; |
| + | /* Flag that something has changed */ |
| + | altered = 1; |
| /* if we're not doing this globally, get out now */ | |
| if (sed_cmd->which_match != 0) | |
| break; | |
| next: | |
| - | if (*line == '\0') |
| - | break; |
| + | /* Exit if we are at EOL and already tried matching at it */ |
| + | if (*line == '\0') { |
| + | if (tried_at_eol) |
| + | break; |
| + | tried_at_eol = 1; |
| + | } |
| //maybe (G.regmatch[0].rm_eo ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL? | |
| } while (regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH); | |
| @@ -1127,7 +1147,7 @@ static void process_files(void) | |
| case 's': | |
| if (!do_subst_command(sed_cmd, &pattern_space)) | |
| break; | |
| - | dbg("do_subst_command succeeeded:'%s'", pattern_space); |
| + | dbg("do_subst_command succeeded:'%s'", pattern_space); |
| substituted |= 1; | |
| /* handle p option */ | |
testsuite/sed.tests+8 -2
| @@ -52,10 +52,8 @@ testing "sed with empty match" "sed 's/z*//g'" "string\n" "" "string\n" | |
| testing "sed s//p" "sed -e s/foo/bar/p -e s/bar/baz/p" "bar\nbaz\nbaz\n" \ | |
| "" "foo\n" | |
| testing "sed -n s//p" "sed -ne s/abc/def/p" "def\n" "" "abc\n" | |
| - | test x"$SKIP_KNOWN_BUGS" = x"" && { |
| testing "sed s//g (exhaustive)" "sed -e 's/[[:space:]]*/,/g'" ",1,2,3,4,5,\n" \ | |
| "" "12345\n" | |
| - | } |
| testing "sed s arbitrary delimiter" "sed -e 's woo boing '" "boing\n" "" "woo\n" | |
| testing "sed s chains" "sed -e s/foo/bar/ -e s/bar/baz/" "baz\n" "" "foo\n" | |
| testing "sed s chains2" "sed -e s/foo/bar/ -e s/baz/nee/" "bar\n" "" "foo\n" | |
| @@ -296,6 +294,14 @@ testing "sed -i finishes ranges correctly" \ | |
| "sed '1,2d' -i input; echo \$?; cat input" \ | |
| "0\n3\n4\n" "1\n2\n3\n4\n" "" | |
| + | testing "sed zero chars match/replace advances correctly 1" \ |
| + | "sed 's/l*/@/g'" \ |
| + | "@h@e@o@\n" "" "helllo\n" |
| + | |
| + | testing "sed zero chars match/replace advances correctly 2" \ |
| + | "sed 's [^ .]* x g'" \ |
| + | "x x.x\n" "" " a.b\n" |
| + | |
| # testing "description" "commands" "result" "infile" "stdin" | |
| exit $FAILCOUNT | |