xdiff: PATIENCE/HISTOGRAM are not independent option bits
[gitweb.git] / help.c
diff --git a/help.c b/help.c
index fd87bb5aeec82beec600be46248b19b13bb33804..cbbe966f685b276cac702bb0fd9a44bfbf5f0e79 100644 (file)
--- a/help.c
+++ b/help.c
@@ -3,6 +3,7 @@
 #include "exec_cmd.h"
 #include "levenshtein.h"
 #include "help.h"
+#include "common-cmds.h"
 
 /* most GUI terminals set COLUMNS (although some don't export it) */
 static int term_columns(void)
@@ -100,7 +101,7 @@ static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 
        if (space < max_cols)
                cols = max_cols / space;
-       rows = (cmds->cnt + cols - 1) / cols;
+       rows = DIV_ROUND_UP(cmds->cnt, cols);
 
        for (i = 0; i < rows; i++) {
                printf("  ");
@@ -126,8 +127,11 @@ static int is_executable(const char *name)
            !S_ISREG(st.st_mode))
                return 0;
 
-#ifdef __MINGW32__
-       /* cannot trust the executable bit, peek into the file instead */
+#if defined(WIN32) || defined(__CYGWIN__)
+#if defined(__CYGWIN__)
+if ((st.st_mode & S_IXUSR) == 0)
+#endif
+{      /* cannot trust the executable bit, peek into the file instead */
        char buf[3] = { 0 };
        int n;
        int fd = open(name, O_RDONLY);
@@ -140,6 +144,7 @@ static int is_executable(const char *name)
                                st.st_mode |= S_IXUSR;
                close(fd);
        }
+}
 #endif
        return st.st_mode & S_IXUSR;
 }
@@ -296,13 +301,21 @@ static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
        old->names = NULL;
 }
 
+/* An empirically derived magic number */
+#define SIMILARITY_FLOOR 7
+#define SIMILAR_ENOUGH(x) ((x) < SIMILARITY_FLOOR)
+
+static const char bad_interpreter_advice[] =
+       N_("'%s' appears to be a git command, but we were not\n"
+       "able to execute it. Maybe git-%s is broken?");
+
 const char *help_unknown_cmd(const char *cmd)
 {
        int i, n, best_similarity = 0;
        struct cmdnames main_cmds, other_cmds;
 
        memset(&main_cmds, 0, sizeof(main_cmds));
-       memset(&other_cmds, 0, sizeof(main_cmds));
+       memset(&other_cmds, 0, sizeof(other_cmds));
        memset(&aliases, 0, sizeof(aliases));
 
        git_config(git_unknown_cmd_config, NULL);
@@ -315,10 +328,36 @@ const char *help_unknown_cmd(const char *cmd)
              sizeof(main_cmds.names), cmdname_compare);
        uniq(&main_cmds);
 
-       /* This reuses cmdname->len for similarity index */
-       for (i = 0; i < main_cmds.cnt; ++i)
+       /* This abuses cmdname->len for levenshtein distance */
+       for (i = 0, n = 0; i < main_cmds.cnt; i++) {
+               int cmp = 0; /* avoid compiler stupidity */
+               const char *candidate = main_cmds.names[i]->name;
+
+               /*
+                * An exact match means we have the command, but
+                * for some reason exec'ing it gave us ENOENT; probably
+                * it's a bad interpreter in the #! line.
+                */
+               if (!strcmp(candidate, cmd))
+                       die(_(bad_interpreter_advice), cmd, cmd);
+
+               /* Does the candidate appear in common_cmds list? */
+               while (n < ARRAY_SIZE(common_cmds) &&
+                      (cmp = strcmp(common_cmds[n].name, candidate)) < 0)
+                       n++;
+               if ((n < ARRAY_SIZE(common_cmds)) && !cmp) {
+                       /* Yes, this is one of the common commands */
+                       n++; /* use the entry from common_cmds[] */
+                       if (!prefixcmp(candidate, cmd)) {
+                               /* Give prefix match a very good score */
+                               main_cmds.names[i]->len = 0;
+                               continue;
+                       }
+               }
+
                main_cmds.names[i]->len =
-                       levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
+                       levenshtein(cmd, candidate, 0, 2, 1, 4) + 1;
+       }
 
        qsort(main_cmds.names, main_cmds.cnt,
              sizeof(*main_cmds.names), levenshtein_compare);
@@ -326,15 +365,26 @@ const char *help_unknown_cmd(const char *cmd)
        if (!main_cmds.cnt)
                die ("Uh oh. Your system reports no Git commands at all.");
 
-       best_similarity = main_cmds.names[0]->len;
-       n = 1;
-       while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
-               ++n;
-       if (autocorrect && n == 1) {
+       /* skip and count prefix matches */
+       for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
+               ; /* still counting */
+
+       if (main_cmds.cnt <= n) {
+               /* prefix matches with everything? that is too ambiguous */
+               best_similarity = SIMILARITY_FLOOR + 1;
+       } else {
+               /* count all the most similar ones */
+               for (best_similarity = main_cmds.names[n++]->len;
+                    (n < main_cmds.cnt &&
+                     best_similarity == main_cmds.names[n]->len);
+                    n++)
+                       ; /* still counting */
+       }
+       if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
                const char *assumed = main_cmds.names[0]->name;
                main_cmds.names[0] = NULL;
                clean_cmdnames(&main_cmds);
-               fprintf(stderr, "WARNING: You called a Git program named '%s', "
+               fprintf(stderr, "WARNING: You called a Git command named '%s', "
                        "which does not exist.\n"
                        "Continuing under the assumption that you meant '%s'\n",
                        cmd, assumed);
@@ -346,9 +396,9 @@ const char *help_unknown_cmd(const char *cmd)
                return assumed;
        }
 
-       fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
+       fprintf(stderr, "git: '%s' is not a git command. See 'git --help'.\n", cmd);
 
-       if (best_similarity < 6) {
+       if (SIMILAR_ENOUGH(best_similarity)) {
                fprintf(stderr, "\nDid you mean %s?\n",
                        n < 2 ? "this": "one of these");