Added Packing Heursitics IRC writeup.
[gitweb.git] / config.c
index bbcafff29f115d3cb1e42d6eb945a857e6aea447..95ec34923d3fcf4d2a8fa16cbab9a5cbfe8e4f6f 100644 (file)
--- a/config.c
+++ b/config.c
@@ -11,6 +11,7 @@
 #define MAXNAME (256)
 
 static FILE *config_file;
+static const char *config_file_name;
 static int config_linenr;
 static int get_next_char(void)
 {
@@ -143,7 +144,7 @@ static int get_base_var(char *name)
                        return -1;
                if (c == ']')
                        return baselen;
-               if (!isalnum(c))
+               if (!isalnum(c) && c != '.')
                        return -1;
                if (baselen > MAXNAME / 2)
                        return -1;
@@ -186,7 +187,7 @@ static int git_parse_file(config_fn_t fn)
                if (get_value(fn, var, baselen+1) < 0)
                        break;
        }
-       die("bad config file line %d", config_linenr);
+       die("bad config file line %d in %s", config_linenr, config_file_name);
 }
 
 int git_config_int(const char *name, const char *value)
@@ -197,7 +198,7 @@ int git_config_int(const char *name, const char *value)
                if (!*end)
                        return val;
        }
-       die("bad config value for '%s'", name);
+       die("bad config value for '%s' in %s", name, config_file_name);
 }
 
 int git_config_bool(const char *name, const char *value)
@@ -221,11 +222,21 @@ int git_default_config(const char *var, const char *value)
                return 0;
        }
 
+       if (!strcmp(var, "core.ignorestat")) {
+               assume_unchanged = git_config_bool(var, value);
+               return 0;
+       }
+
        if (!strcmp(var, "core.symrefsonly")) {
                only_use_symrefs = git_config_bool(var, value);
                return 0;
        }
 
+       if (!strcmp(var, "core.warnambiguousrefs")) {
+               warn_ambiguous_refs = git_config_bool(var, value);
+               return 0;
+       }
+
        if (!strcmp(var, "user.name")) {
                strncpy(git_default_name, value, sizeof(git_default_name));
                return 0;
@@ -236,8 +247,8 @@ int git_default_config(const char *var, const char *value)
                return 0;
        }
 
-       if (!strcmp(var, "diff.renamelimit")) {
-               diff_rename_limit_default = git_config_int(var, value);
+       if (!strcmp(var, "i18n.commitencoding")) {
+               strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
                return 0;
        }
 
@@ -245,46 +256,68 @@ int git_default_config(const char *var, const char *value)
        return 0;
 }
 
-int git_config(config_fn_t fn)
+int git_config_from_file(config_fn_t fn, const char *filename)
 {
        int ret;
-       FILE *f = fopen(git_path("config"), "r");
+       FILE *f = fopen(filename, "r");
 
        ret = -1;
        if (f) {
                config_file = f;
+               config_file_name = filename;
                config_linenr = 1;
                ret = git_parse_file(fn);
                fclose(f);
+               config_file_name = NULL;
        }
        return ret;
 }
 
+int git_config(config_fn_t fn)
+{
+       return git_config_from_file(fn, git_path("config"));
+}
+
 /*
  * Find all the stuff for git_config_set() below.
  */
+
+#define MAX_MATCHES 512
+
 static struct {
        int baselen;
        char* key;
+       int do_not_match;
        regex_t* value_regex;
-       off_t offset;
+       int multi_replace;
+       off_t offset[MAX_MATCHES];
        enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
        int seen;
 } store;
 
+static int matches(const char* key, const char* value)
+{
+       return !strcmp(key, store.key) &&
+               (store.value_regex == NULL ||
+                (store.do_not_match ^
+                 !regexec(store.value_regex, value, 0, NULL, 0)));
+}
+
 static int store_aux(const char* key, const char* value)
 {
        switch (store.state) {
        case KEY_SEEN:
-               if (!strcmp(key, store.key) &&
-                               (store.value_regex == NULL ||
-                               !regexec(store.value_regex, value, 0, NULL, 0))) {
-                       if (store.seen == 1) {
+               if (matches(key, value)) {
+                       if (store.seen == 1 && store.multi_replace == 0) {
                                fprintf(stderr,
                                        "Warning: %s has multiple values\n",
                                        key);
+                       } else if (store.seen >= MAX_MATCHES) {
+                               fprintf(stderr, "Too many matches\n");
+                               return 1;
                        }
-                       store.offset = ftell(config_file);
+
+                       store.offset[store.seen] = ftell(config_file);
                        store.seen++;
                }
                break;
@@ -293,14 +326,13 @@ static int store_aux(const char* key, const char* value)
                        store.state = SECTION_END_SEEN;
                        break;
                } else
-                       store.offset = ftell(config_file);
+                       /* do not increment matches: this is no match */
+                       store.offset[store.seen] = ftell(config_file);
                /* fallthru */
        case SECTION_END_SEEN:
        case START:
-               if (!strcmp(key, store.key) &&
-                               (store.value_regex == NULL ||
-                               !regexec(store.value_regex, value, 0, NULL, 0))) {
-                       store.offset = ftell(config_file);
+               if (matches(key, value)) {
+                       store.offset[store.seen] = ftell(config_file);
                        store.state = KEY_SEEN;
                        store.seen++;
                } else if(!strncmp(key, store.key, store.baselen))
@@ -334,14 +366,38 @@ static void store_write_pair(int fd, const char* key, const char* value)
        write(fd, "\n", 1);
 }
 
+static int find_beginning_of_line(const char* contents, int size,
+       int offset_, int* found_bracket)
+{
+       int equal_offset = size, bracket_offset = size;
+       int offset;
+
+       for (offset = offset_-2; offset > 0 
+                       && contents[offset] != '\n'; offset--)
+               switch (contents[offset]) {
+                       case '=': equal_offset = offset; break;
+                       case ']': bracket_offset = offset; break;
+               }
+       if (bracket_offset < equal_offset) {
+               *found_bracket = 1;
+               offset = bracket_offset+1;
+       } else
+               offset++;
+
+       return offset;
+}
+
 int git_config_set(const char* key, const char* value)
 {
-       return git_config_set_multivar(key, value, NULL);
+       return git_config_set_multivar(key, value, NULL, 0);
 }
 
 /*
  * If value==NULL, unset in (remove from) config,
  * if value_regex!=NULL, disregard key/value pairs where value does not match.
+ * if multi_replace==0, nothing, or only one matching key/value is replaced,
+ *     else all matching key/values (regardless how many) are removed,
+ *     before the new pair is written.
  *
  * Returns 0 on success.
  *
@@ -360,38 +416,41 @@ int git_config_set(const char* key, const char* value)
  *
  */
 int git_config_set_multivar(const char* key, const char* value,
-       const char* value_regex)
+       const char* value_regex, int multi_replace)
 {
        int i;
-       struct stat st;
-       int fd;
-       char* config_file = strdup(git_path("config"));
+       int fd, in_fd;
+       char* config_filename = strdup(git_path("config"));
        char* lock_file = strdup(git_path("config.lock"));
+       const char* last_dot = strrchr(key, '.');
 
        /*
         * Since "key" actually contains the section name and the real
         * key name separated by a dot, we have to know where the dot is.
         */
-       for (store.baselen = 0;
-                       key[store.baselen] != '.' && key[store.baselen];
-                       store.baselen++);
-       if (!key[store.baselen] || !key[store.baselen+1]) {
+
+       if (last_dot == NULL) { 
                fprintf(stderr, "key does not contain a section: %s\n", key);
                return 2;
        }
+       store.baselen = last_dot - key;
+
+       store.multi_replace = multi_replace;
 
        /*
         * Validate the key and while at it, lower case it for matching.
         */
        store.key = (char*)malloc(strlen(key)+1);
        for (i = 0; key[i]; i++)
-               if (i != store.baselen && (!isalnum(key[i]) ||
-                               (i == store.baselen+1 && !isalpha(key[i])))) {
+               if (i != store.baselen &&
+                               ((!isalnum(key[i]) && key[i] != '.') ||
+                                (i == store.baselen+1 && !isalpha(key[i])))) {
                        fprintf(stderr, "invalid key: %s\n", key);
                        free(store.key);
                        return 1;
                } else
                        store.key[i] = tolower(key[i]);
+       store.key[i] = 0;
 
        /*
         * The lock_file serves a purpose in addition to locking: the new
@@ -407,15 +466,17 @@ int git_config_set_multivar(const char* key, const char* value,
        /*
         * If .git/config does not exist yet, write a minimal version.
         */
-       if (stat(config_file, &st)) {
-               static const char contents[] =
-                       "#\n"
-                       "# This is the config file\n"
-                       "#\n"
-                       "\n";
-
+       in_fd = open(config_filename, O_RDONLY);
+       if ( in_fd < 0 ) {
                free(store.key);
 
+               if ( ENOENT != errno ) {
+                       error("opening %s: %s", config_filename,
+                             strerror(errno));
+                       close(fd);
+                       unlink(lock_file);
+                       return 3; /* same as "invalid config file" */
+               }
                /* if nothing to unset, error out */
                if (value == NULL) {
                        close(fd);
@@ -424,29 +485,33 @@ int git_config_set_multivar(const char* key, const char* value,
                }
 
                store.key = (char*)key;
-
-               write(fd, contents, sizeof(contents)-1);
                store_write_section(fd, key);
                store_write_pair(fd, key, value);
        } else{
-               int in_fd;
+               struct stat st;
                char* contents;
-               int offset, new_line = 0;
+               int i, copy_begin, copy_end, new_line = 0;
 
                if (value_regex == NULL)
                        store.value_regex = NULL;
                else {
+                       if (value_regex[0] == '!') {
+                               store.do_not_match = 1;
+                               value_regex++;
+                       } else
+                               store.do_not_match = 0;
+
                        store.value_regex = (regex_t*)malloc(sizeof(regex_t));
                        if (regcomp(store.value_regex, value_regex,
                                        REG_EXTENDED)) {
-                               fprintf(stderr, "Invalid pattern: %s",
+                               fprintf(stderr, "Invalid pattern: %s\n",
                                        value_regex);
                                free(store.value_regex);
                                return 6;
                        }
                }
 
-               store.offset = 0;
+               store.offset[0] = 0;
                store.state = START;
                store.seen = 0;
 
@@ -472,52 +537,42 @@ int git_config_set_multivar(const char* key, const char* value,
                        free(store.value_regex);
                }
 
-               /* if nothing to unset, error out */
-               if (store.seen == 0 && value == NULL) {
+               /* if nothing to unset, or too many matches, error out */
+               if ((store.seen == 0 && value == NULL) ||
+                               (store.seen > 1 && multi_replace == 0)) {
                        close(fd);
                        unlink(lock_file);
                        return 5;
                }
 
-               store.key = (char*)key;
-
-               in_fd = open(config_file, O_RDONLY, 0666);
+               fstat(in_fd, &st);
                contents = mmap(NULL, st.st_size, PROT_READ,
                        MAP_PRIVATE, in_fd, 0);
                close(in_fd);
 
-               if (store.offset == 0) {
-                       store.offset = offset = st.st_size;
-               } else if (store.state != KEY_SEEN) {
-                       offset = store.offset;
-               } else {
-                       int equal_offset = st.st_size,
-                               bracket_offset = st.st_size;
-
-                       if (value == NULL && store.seen > 1) {
-                               fprintf(stderr, "Cannot remove multivar (%s has %d values\n", key, store.seen);
-                               close(fd);
-                               unlink(lock_file);
-                               return 7;
-                       }
-                       for (offset = store.offset-2; offset > 0 
-                                       && contents[offset] != '\n'; offset--)
-                               switch (contents[offset]) {
-                               case '=': equal_offset = offset; break;
-                               case ']': bracket_offset = offset; break;
-                               }
-                       if (bracket_offset < equal_offset) {
-                               new_line = 1;
-                               offset = bracket_offset+1;
+               if (store.seen == 0)
+                       store.seen = 1;
+
+               for (i = 0, copy_begin = 0; i < store.seen; i++) {
+                       if (store.offset[i] == 0) {
+                               store.offset[i] = copy_end = st.st_size;
+                       } else if (store.state != KEY_SEEN) {
+                               copy_end = store.offset[i];
                        } else
-                               offset++;
+                               copy_end = find_beginning_of_line(
+                                       contents, st.st_size,
+                                       store.offset[i]-2, &new_line);
+
+                       /* write the first part of the config */
+                       if (copy_end > copy_begin) {
+                               write(fd, contents + copy_begin,
+                               copy_end - copy_begin);
+                               if (new_line)
+                                       write(fd, "\n", 1);
+                       }
+                       copy_begin = store.offset[i];
                }
 
-               /* write the first part of the config */
-               write(fd, contents, offset);
-               if (new_line)
-                       write(fd, "\n", 1);
-
                /* write the pair (value == NULL means unset) */
                if (value != NULL) {
                        if (store.state == START)
@@ -526,17 +581,17 @@ int git_config_set_multivar(const char* key, const char* value,
                }
 
                /* write the rest of the config */
-               if (store.offset < st.st_size)
-                       write(fd, contents + store.offset,
-                               st.st_size - store.offset);
+               if (copy_begin < st.st_size)
+                       write(fd, contents + copy_begin,
+                               st.st_size - copy_begin);
 
                munmap(contents, st.st_size);
-               unlink(config_file);
+               unlink(config_filename);
        }
 
        close(fd);
 
-       if (rename(lock_file, config_file) < 0) {
+       if (rename(lock_file, config_filename) < 0) {
                fprintf(stderr, "Could not rename the lock file?\n");
                return 4;
        }
@@ -544,3 +599,4 @@ int git_config_set_multivar(const char* key, const char* value,
        return 0;
 }
 
+