Code

git-svn: correctly access repos when only given partial read permissions
[git.git] / builtin-grep.c
index 93b7e07b30ced0b4f4bad544d9bd8dbedadf452c..ad7dc00cde4e8e08ef35b313525781c135357df3 100644 (file)
@@ -11,6 +11,7 @@
 #include "tree-walk.h"
 #include "builtin.h"
 #include <regex.h>
+#include "grep.h"
 #include <fnmatch.h>
 #include <sys/wait.h>
 
@@ -82,569 +83,40 @@ static int pathspec_matches(const char **paths, const char *name)
        return 0;
 }
 
-enum grep_pat_token {
-       GREP_PATTERN,
-       GREP_AND,
-       GREP_OPEN_PAREN,
-       GREP_CLOSE_PAREN,
-       GREP_NOT,
-       GREP_OR,
-};
-
-struct grep_pat {
-       struct grep_pat *next;
-       const char *origin;
-       int no;
-       enum grep_pat_token token;
-       const char *pattern;
-       regex_t regexp;
-};
-
-enum grep_expr_node {
-       GREP_NODE_ATOM,
-       GREP_NODE_NOT,
-       GREP_NODE_AND,
-       GREP_NODE_OR,
-};
-
-struct grep_expr {
-       enum grep_expr_node node;
-       union {
-               struct grep_pat *atom;
-               struct grep_expr *unary;
-               struct {
-                       struct grep_expr *left;
-                       struct grep_expr *right;
-               } binary;
-       } u;
-};
-
-struct grep_opt {
-       struct grep_pat *pattern_list;
-       struct grep_pat **pattern_tail;
-       struct grep_expr *pattern_expression;
-       regex_t regexp;
-       unsigned linenum:1;
-       unsigned invert:1;
-       unsigned name_only:1;
-       unsigned unmatch_name_only:1;
-       unsigned count:1;
-       unsigned word_regexp:1;
-       unsigned fixed:1;
-#define GREP_BINARY_DEFAULT    0
-#define GREP_BINARY_NOMATCH    1
-#define GREP_BINARY_TEXT       2
-       unsigned binary:2;
-       unsigned extended:1;
-       int regflags;
-       unsigned pre_context;
-       unsigned post_context;
-};
-
-static void add_pattern(struct grep_opt *opt, const char *pat,
-                       const char *origin, int no, enum grep_pat_token t)
-{
-       struct grep_pat *p = xcalloc(1, sizeof(*p));
-       p->pattern = pat;
-       p->origin = origin;
-       p->no = no;
-       p->token = t;
-       *opt->pattern_tail = p;
-       opt->pattern_tail = &p->next;
-       p->next = NULL;
-}
-
-static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
-{
-       int err = regcomp(&p->regexp, p->pattern, opt->regflags);
-       if (err) {
-               char errbuf[1024];
-               char where[1024];
-               if (p->no)
-                       sprintf(where, "In '%s' at %d, ",
-                               p->origin, p->no);
-               else if (p->origin)
-                       sprintf(where, "%s, ", p->origin);
-               else
-                       where[0] = 0;
-               regerror(err, &p->regexp, errbuf, 1024);
-               regfree(&p->regexp);
-               die("%s'%s': %s", where, p->pattern, errbuf);
-       }
-}
-
-#if DEBUG
-static inline void indent(int in)
-{
-       int i;
-       for (i = 0; i < in; i++) putchar(' ');
-}
-
-static void dump_pattern_exp(struct grep_expr *x, int in)
-{
-       switch (x->node) {
-       case GREP_NODE_ATOM:
-               indent(in);
-               puts(x->u.atom->pattern);
-               break;
-       case GREP_NODE_NOT:
-               indent(in);
-               puts("--not");
-               dump_pattern_exp(x->u.unary, in+1);
-               break;
-       case GREP_NODE_AND:
-               dump_pattern_exp(x->u.binary.left, in+1);
-               indent(in);
-               puts("--and");
-               dump_pattern_exp(x->u.binary.right, in+1);
-               break;
-       case GREP_NODE_OR:
-               dump_pattern_exp(x->u.binary.left, in+1);
-               indent(in);
-               puts("--or");
-               dump_pattern_exp(x->u.binary.right, in+1);
-               break;
-       }
-}
-
-static void looking_at(const char *msg, struct grep_pat **list)
-{
-       struct grep_pat *p = *list;
-       fprintf(stderr, "%s: looking at ", msg);
-       if (!p)
-               fprintf(stderr, "empty\n");
-       else
-               fprintf(stderr, "<%s>\n", p->pattern);
-}
-#else
-#define looking_at(a,b) do {} while(0)
-#endif
-
-static struct grep_expr *compile_pattern_expr(struct grep_pat **);
-static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
-{
-       struct grep_pat *p;
-       struct grep_expr *x;
-
-       looking_at("atom", list);
-
-       p = *list;
-       switch (p->token) {
-       case GREP_PATTERN: /* atom */
-               x = xcalloc(1, sizeof (struct grep_expr));
-               x->node = GREP_NODE_ATOM;
-               x->u.atom = p;
-               *list = p->next;
-               return x;
-       case GREP_OPEN_PAREN:
-               *list = p->next;
-               x = compile_pattern_expr(list);
-               if (!x)
-                       return NULL;
-               if (!*list || (*list)->token != GREP_CLOSE_PAREN)
-                       die("unmatched parenthesis");
-               *list = (*list)->next;
-               return x;
-       default:
-               return NULL;
-       }
-}
-
-static struct grep_expr *compile_pattern_not(struct grep_pat **list)
-{
-       struct grep_pat *p;
-       struct grep_expr *x;
-
-       looking_at("not", list);
-
-       p = *list;
-       switch (p->token) {
-       case GREP_NOT:
-               if (!p->next)
-                       die("--not not followed by pattern expression");
-               *list = p->next;
-               x = xcalloc(1, sizeof (struct grep_expr));
-               x->node = GREP_NODE_NOT;
-               x->u.unary = compile_pattern_not(list);
-               if (!x->u.unary)
-                       die("--not followed by non pattern expression");
-               return x;
-       default:
-               return compile_pattern_atom(list);
-       }
-}
-
-static struct grep_expr *compile_pattern_and(struct grep_pat **list)
-{
-       struct grep_pat *p;
-       struct grep_expr *x, *y, *z;
-
-       looking_at("and", list);
-
-       x = compile_pattern_not(list);
-       p = *list;
-       if (p && p->token == GREP_AND) {
-               if (!p->next)
-                       die("--and not followed by pattern expression");
-               *list = p->next;
-               y = compile_pattern_and(list);
-               if (!y)
-                       die("--and not followed by pattern expression");
-               z = xcalloc(1, sizeof (struct grep_expr));
-               z->node = GREP_NODE_AND;
-               z->u.binary.left = x;
-               z->u.binary.right = y;
-               return z;
-       }
-       return x;
-}
-
-static struct grep_expr *compile_pattern_or(struct grep_pat **list)
-{
-       struct grep_pat *p;
-       struct grep_expr *x, *y, *z;
-
-       looking_at("or", list);
-
-       x = compile_pattern_and(list);
-       p = *list;
-       if (x && p && p->token != GREP_CLOSE_PAREN) {
-               y = compile_pattern_or(list);
-               if (!y)
-                       die("not a pattern expression %s", p->pattern);
-               z = xcalloc(1, sizeof (struct grep_expr));
-               z->node = GREP_NODE_OR;
-               z->u.binary.left = x;
-               z->u.binary.right = y;
-               return z;
-       }
-       return x;
-}
-
-static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
-{
-       looking_at("expr", list);
-
-       return compile_pattern_or(list);
-}
-
-static void compile_patterns(struct grep_opt *opt)
-{
-       struct grep_pat *p;
-
-       /* First compile regexps */
-       for (p = opt->pattern_list; p; p = p->next) {
-               if (p->token == GREP_PATTERN)
-                       compile_regexp(p, opt);
-               else
-                       opt->extended = 1;
-       }
-
-       if (!opt->extended)
-               return;
-
-       /* Then bundle them up in an expression.
-        * A classic recursive descent parser would do.
-        */
-       p = opt->pattern_list;
-       opt->pattern_expression = compile_pattern_expr(&p);
-#if DEBUG
-       dump_pattern_exp(opt->pattern_expression, 0);
-#endif
-       if (p)
-               die("incomplete pattern expression: %s", p->pattern);
-}
-
-static char *end_of_line(char *cp, unsigned long *left)
-{
-       unsigned long l = *left;
-       while (l && *cp != '\n') {
-               l--;
-               cp++;
-       }
-       *left = l;
-       return cp;
-}
-
-static int word_char(char ch)
-{
-       return isalnum(ch) || ch == '_';
-}
-
-static void show_line(struct grep_opt *opt, const char *bol, const char *eol,
-                     const char *name, unsigned lno, char sign)
-{
-       printf("%s%c", name, sign);
-       if (opt->linenum)
-               printf("%d%c", lno, sign);
-       printf("%.*s\n", (int)(eol-bol), bol);
-}
-
-/*
- * NEEDSWORK: share code with diff.c
- */
-#define FIRST_FEW_BYTES 8000
-static int buffer_is_binary(const char *ptr, unsigned long size)
-{
-       if (FIRST_FEW_BYTES < size)
-               size = FIRST_FEW_BYTES;
-       if (memchr(ptr, 0, size))
-               return 1;
-       return 0;
-}
-
-static int fixmatch(const char *pattern, char *line, regmatch_t *match)
-{
-       char *hit = strstr(line, pattern);
-       if (!hit) {
-               match->rm_so = match->rm_eo = -1;
-               return REG_NOMATCH;
-       }
-       else {
-               match->rm_so = hit - line;
-               match->rm_eo = match->rm_so + strlen(pattern);
-               return 0;
-       }
-}
-
-static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol)
-{
-       int hit = 0;
-       int at_true_bol = 1;
-       regmatch_t pmatch[10];
-
- again:
-       if (!opt->fixed) {
-               regex_t *exp = &p->regexp;
-               hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
-                              pmatch, 0);
-       }
-       else {
-               hit = !fixmatch(p->pattern, bol, pmatch);
-       }
-
-       if (hit && opt->word_regexp) {
-               if ((pmatch[0].rm_so < 0) ||
-                   (eol - bol) <= pmatch[0].rm_so ||
-                   (pmatch[0].rm_eo < 0) ||
-                   (eol - bol) < pmatch[0].rm_eo)
-                       die("regexp returned nonsense");
-
-               /* Match beginning must be either beginning of the
-                * line, or at word boundary (i.e. the last char must
-                * not be a word char).  Similarly, match end must be
-                * either end of the line, or at word boundary
-                * (i.e. the next char must not be a word char).
-                */
-               if ( ((pmatch[0].rm_so == 0 && at_true_bol) ||
-                     !word_char(bol[pmatch[0].rm_so-1])) &&
-                    ((pmatch[0].rm_eo == (eol-bol)) ||
-                     !word_char(bol[pmatch[0].rm_eo])) )
-                       ;
-               else
-                       hit = 0;
-
-               if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
-                       /* There could be more than one match on the
-                        * line, and the first match might not be
-                        * strict word match.  But later ones could be!
-                        */
-                       bol = pmatch[0].rm_so + bol + 1;
-                       at_true_bol = 0;
-                       goto again;
-               }
-       }
-       return hit;
-}
-
-static int match_expr_eval(struct grep_opt *opt,
-                          struct grep_expr *x,
-                          char *bol, char *eol)
-{
-       switch (x->node) {
-       case GREP_NODE_ATOM:
-               return match_one_pattern(opt, x->u.atom, bol, eol);
-               break;
-       case GREP_NODE_NOT:
-               return !match_expr_eval(opt, x->u.unary, bol, eol);
-       case GREP_NODE_AND:
-               return (match_expr_eval(opt, x->u.binary.left, bol, eol) &&
-                       match_expr_eval(opt, x->u.binary.right, bol, eol));
-       case GREP_NODE_OR:
-               return (match_expr_eval(opt, x->u.binary.left, bol, eol) ||
-                       match_expr_eval(opt, x->u.binary.right, bol, eol));
-       }
-       die("Unexpected node type (internal error) %d\n", x->node);
-}
-
-static int match_expr(struct grep_opt *opt, char *bol, char *eol)
-{
-       struct grep_expr *x = opt->pattern_expression;
-       return match_expr_eval(opt, x, bol, eol);
-}
-
-static int match_line(struct grep_opt *opt, char *bol, char *eol)
-{
-       struct grep_pat *p;
-       if (opt->extended)
-               return match_expr(opt, bol, eol);
-       for (p = opt->pattern_list; p; p = p->next) {
-               if (match_one_pattern(opt, p, bol, eol))
-                       return 1;
-       }
-       return 0;
-}
-
-static int grep_buffer(struct grep_opt *opt, const char *name,
-                      char *buf, unsigned long size)
-{
-       char *bol = buf;
-       unsigned long left = size;
-       unsigned lno = 1;
-       struct pre_context_line {
-               char *bol;
-               char *eol;
-       } *prev = NULL, *pcl;
-       unsigned last_hit = 0;
-       unsigned last_shown = 0;
-       int binary_match_only = 0;
-       const char *hunk_mark = "";
-       unsigned count = 0;
-
-       if (buffer_is_binary(buf, size)) {
-               switch (opt->binary) {
-               case GREP_BINARY_DEFAULT:
-                       binary_match_only = 1;
-                       break;
-               case GREP_BINARY_NOMATCH:
-                       return 0; /* Assume unmatch */
-                       break;
-               default:
-                       break;
-               }
-       }
-
-       if (opt->pre_context)
-               prev = xcalloc(opt->pre_context, sizeof(*prev));
-       if (opt->pre_context || opt->post_context)
-               hunk_mark = "--\n";
-
-       while (left) {
-               char *eol, ch;
-               int hit = 0;
-
-               eol = end_of_line(bol, &left);
-               ch = *eol;
-               *eol = 0;
-
-               hit = match_line(opt, bol, eol);
-
-               /* "grep -v -e foo -e bla" should list lines
-                * that do not have either, so inversion should
-                * be done outside.
-                */
-               if (opt->invert)
-                       hit = !hit;
-               if (opt->unmatch_name_only) {
-                       if (hit)
-                               return 0;
-                       goto next_line;
-               }
-               if (hit) {
-                       count++;
-                       if (binary_match_only) {
-                               printf("Binary file %s matches\n", name);
-                               return 1;
-                       }
-                       if (opt->name_only) {
-                               printf("%s\n", name);
-                               return 1;
-                       }
-                       /* Hit at this line.  If we haven't shown the
-                        * pre-context lines, we would need to show them.
-                        * When asked to do "count", this still show
-                        * the context which is nonsense, but the user
-                        * deserves to get that ;-).
-                        */
-                       if (opt->pre_context) {
-                               unsigned from;
-                               if (opt->pre_context < lno)
-                                       from = lno - opt->pre_context;
-                               else
-                                       from = 1;
-                               if (from <= last_shown)
-                                       from = last_shown + 1;
-                               if (last_shown && from != last_shown + 1)
-                                       printf(hunk_mark);
-                               while (from < lno) {
-                                       pcl = &prev[lno-from-1];
-                                       show_line(opt, pcl->bol, pcl->eol,
-                                                 name, from, '-');
-                                       from++;
-                               }
-                               last_shown = lno-1;
-                       }
-                       if (last_shown && lno != last_shown + 1)
-                               printf(hunk_mark);
-                       if (!opt->count)
-                               show_line(opt, bol, eol, name, lno, ':');
-                       last_shown = last_hit = lno;
-               }
-               else if (last_hit &&
-                        lno <= last_hit + opt->post_context) {
-                       /* If the last hit is within the post context,
-                        * we need to show this line.
-                        */
-                       if (last_shown && lno != last_shown + 1)
-                               printf(hunk_mark);
-                       show_line(opt, bol, eol, name, lno, '-');
-                       last_shown = lno;
-               }
-               if (opt->pre_context) {
-                       memmove(prev+1, prev,
-                               (opt->pre_context-1) * sizeof(*prev));
-                       prev->bol = bol;
-                       prev->eol = eol;
-               }
-
-       next_line:
-               *eol = ch;
-               bol = eol + 1;
-               if (!left)
-                       break;
-               left--;
-               lno++;
-       }
-
-       if (opt->unmatch_name_only) {
-               /* We did not see any hit, so we want to show this */
-               printf("%s\n", name);
-               return 1;
-       }
-
-       /* NEEDSWORK:
-        * The real "grep -c foo *.c" gives many "bar.c:0" lines,
-        * which feels mostly useless but sometimes useful.  Maybe
-        * make it another option?  For now suppress them.
-        */
-       if (opt->count && count)
-               printf("%s:%u\n", name, count);
-       return !!last_hit;
-}
-
-static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name)
+static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 {
        unsigned long size;
        char *data;
        char type[20];
+       char *to_free = NULL;
        int hit;
+
        data = read_sha1_file(sha1, type, &size);
        if (!data) {
                error("'%s': unable to read %s", name, sha1_to_hex(sha1));
                return 0;
        }
+       if (opt->relative && opt->prefix_length) {
+               static char name_buf[PATH_MAX];
+               char *cp;
+               int name_len = strlen(name) - opt->prefix_length + 1;
+
+               if (!tree_name_len)
+                       name += opt->prefix_length;
+               else {
+                       if (ARRAY_SIZE(name_buf) <= name_len)
+                               cp = to_free = xmalloc(name_len);
+                       else
+                               cp = name_buf;
+                       memcpy(cp, name, tree_name_len);
+                       strcpy(cp + tree_name_len,
+                              name + tree_name_len + opt->prefix_length);
+                       name = cp;
+               }
+       }
        hit = grep_buffer(opt, name, data, size);
        free(data);
+       free(to_free);
        return hit;
 }
 
@@ -674,6 +146,8 @@ static int grep_file(struct grep_opt *opt, const char *filename)
                return 0;
        }
        close(i);
+       if (opt->relative && opt->prefix_length)
+               filename += opt->prefix_length;
        i = grep_buffer(opt, filename, data, st.st_size);
        free(data);
        return i;
@@ -720,7 +194,7 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
        char *argptr = randarg;
        struct grep_pat *p;
 
-       if (opt->extended)
+       if (opt->extended || (opt->relative && opt->prefix_length))
                return -1;
        len = nr = 0;
        push_arg("grep");
@@ -728,6 +202,8 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
                push_arg("-F");
        if (opt->linenum)
                push_arg("-n");
+       if (!opt->pathname)
+               push_arg("-h");
        if (opt->regflags & REG_EXTENDED)
                push_arg("-E");
        if (opt->regflags & REG_ICASE)
@@ -845,10 +321,11 @@ static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
                if (!pathspec_matches(paths, ce->name))
                        continue;
                if (cached)
-                       hit |= grep_sha1(opt, ce->sha1, ce->name);
+                       hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
                else
                        hit |= grep_file(opt, ce->name);
        }
+       free_grep_patterns(opt);
        return hit;
 }
 
@@ -860,11 +337,12 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
        int hit = 0;
        struct name_entry entry;
        char *down;
-       char *path_buf = xmalloc(PATH_MAX + strlen(tree_name) + 100);
+       int tn_len = strlen(tree_name);
+       char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
 
-       if (tree_name[0]) {
-               int offset = sprintf(path_buf, "%s:", tree_name);
-               down = path_buf + offset;
+       if (tn_len) {
+               tn_len = sprintf(path_buf, "%s:", tree_name);
+               down = path_buf + tn_len;
                strcat(down, base);
        }
        else {
@@ -886,7 +364,7 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
                if (!pathspec_matches(paths, down))
                        ;
                else if (S_ISREG(entry.mode))
-                       hit |= grep_sha1(opt, entry.sha1, path_buf);
+                       hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
                else if (S_ISDIR(entry.mode)) {
                        char type[20];
                        struct tree_desc sub;
@@ -907,7 +385,7 @@ static int grep_object(struct grep_opt *opt, const char **paths,
                       struct object *obj, const char *name)
 {
        if (obj->type == OBJ_BLOB)
-               return grep_sha1(opt, obj->sha1, name);
+               return grep_sha1(opt, obj->sha1, name, 0);
        if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
                struct tree_desc tree;
                void *data;
@@ -945,6 +423,9 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
        int i;
 
        memset(&opt, 0, sizeof(opt));
+       opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
+       opt.relative = 1;
+       opt.pathname = 1;
        opt.pattern_tail = &opt.pattern_list;
        opt.regflags = REG_NEWLINE;
 
@@ -1004,10 +485,12 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                        opt.linenum = 1;
                        continue;
                }
+               if (!strcmp("-h", arg)) {
+                       opt.pathname = 0;
+                       continue;
+               }
                if (!strcmp("-H", arg)) {
-                       /* We always show the pathname, so this
-                        * is a noop.
-                        */
+                       opt.pathname = 1;
                        continue;
                }
                if (!strcmp("-l", arg) ||
@@ -1082,8 +565,9 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                                /* ignore empty line like grep does */
                                if (!buf[0])
                                        continue;
-                               add_pattern(&opt, strdup(buf), argv[1], ++lno,
-                                           GREP_PATTERN);
+                               append_grep_pattern(&opt, xstrdup(buf),
+                                                   argv[1], ++lno,
+                                                   GREP_PATTERN);
                        }
                        fclose(patterns);
                        argv++;
@@ -1091,33 +575,46 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                        continue;
                }
                if (!strcmp("--not", arg)) {
-                       add_pattern(&opt, arg, "command line", 0, GREP_NOT);
+                       append_grep_pattern(&opt, arg, "command line", 0,
+                                           GREP_NOT);
                        continue;
                }
                if (!strcmp("--and", arg)) {
-                       add_pattern(&opt, arg, "command line", 0, GREP_AND);
+                       append_grep_pattern(&opt, arg, "command line", 0,
+                                           GREP_AND);
                        continue;
                }
                if (!strcmp("--or", arg))
                        continue; /* no-op */
                if (!strcmp("(", arg)) {
-                       add_pattern(&opt, arg, "command line", 0, GREP_OPEN_PAREN);
+                       append_grep_pattern(&opt, arg, "command line", 0,
+                                           GREP_OPEN_PAREN);
                        continue;
                }
                if (!strcmp(")", arg)) {
-                       add_pattern(&opt, arg, "command line", 0, GREP_CLOSE_PAREN);
+                       append_grep_pattern(&opt, arg, "command line", 0,
+                                           GREP_CLOSE_PAREN);
+                       continue;
+               }
+               if (!strcmp("--all-match", arg)) {
+                       opt.all_match = 1;
                        continue;
                }
                if (!strcmp("-e", arg)) {
                        if (1 < argc) {
-                               add_pattern(&opt, argv[1], "-e option", 0,
-                                           GREP_PATTERN);
+                               append_grep_pattern(&opt, argv[1],
+                                                   "-e option", 0,
+                                                   GREP_PATTERN);
                                argv++;
                                argc--;
                                continue;
                        }
                        die(emsg_missing_argument, arg);
                }
+               if (!strcmp("--full-name", arg)) {
+                       opt.relative = 0;
+                       continue;
+               }
                if (!strcmp("--", arg)) {
                        /* later processing wants to have this at argv[1] */
                        argv--;
@@ -1129,8 +626,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 
                /* First unrecognized non-option token */
                if (!opt.pattern_list) {
-                       add_pattern(&opt, arg, "command line", 0,
-                                   GREP_PATTERN);
+                       append_grep_pattern(&opt, arg, "command line", 0,
+                                           GREP_PATTERN);
                        break;
                }
                else {
@@ -1147,8 +644,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                die("no pattern given.");
        if ((opt.regflags != REG_NEWLINE) && opt.fixed)
                die("cannot mix --fixed-strings and regexp");
-       if (!opt.fixed)
-               compile_patterns(&opt);
+       compile_grep_patterns(&opt);
 
        /* Check revs and then paths */
        for (i = 1; i < argc; i++) {
@@ -1176,8 +672,15 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                        verify_filename(prefix, argv[j]);
        }
 
-       if (i < argc)
+       if (i < argc) {
                paths = get_pathspec(prefix, argv + i);
+               if (opt.prefix_length && opt.relative) {
+                       /* Make sure we do not get outside of paths */
+                       for (i = 0; paths[i]; i++)
+                               if (strncmp(prefix, paths[i], opt.prefix_length))
+                                       die("git-grep: cannot generate relative filenames containing '..'");
+               }
+       }
        else if (prefix) {
                paths = xcalloc(2, sizeof(const char *));
                paths[0] = prefix;
@@ -1196,5 +699,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                if (grep_object(&opt, paths, real_obj, list.objects[i].name))
                        hit = 1;
        }
+       free_grep_patterns(&opt);
        return !hit;
 }