man: fix following links if run inside manpage dir

function                                             old     new   delta
run_man_pipe                                         369     420     +51

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 28 insertions, 16 deletions

diff --git a/miscutils/man.c b/miscutils/man.c
index 6fa1fbfdc..b3d20bd08 100644
--- a/miscutils/man.c
+++ b/miscutils/man.c
@@ -73,7 +73,7 @@ struct globals {
 
 static int show_manpage(char *man_filename, int man, int level);
 
-static int run_pipe(char *man_filename, int man, int level)
+static int run_man_pipe(char *man_filename, int man, int level)
 {
         char *cmd;
 
@@ -115,24 +115,36 @@ static int run_pipe(char *man_filename, int man, int level)
                  * ".so man7/path_resolution.7\n<junk>"
                  */
                 *strchrnul(line, '\n') = '\0';
-                linkname = skip_whitespace(&line[4]);
-
-                /* If link has no slashes, we just replace man page name.
-                 * If link has slashes (however many), we go back *once*.
-                 * ".so zzz/ggg/page.3" does NOT go back two levels. */
+                linkname = skip_whitespace(line + 4);
+//testcase:
+// cd /usr/share/man/man2
+// man ./path_resolution.2.gz
+                while (man_filename[0] == '.' && man_filename[1] == '/')
+                        man_filename += 2;
                 p = strrchr(man_filename, '/');
                 if (!p)
-                        goto ordinary_manpage;
-                *p = '\0';
+                        man_filename = (char*)".." + 1; /* "NAME.N" -> "." */
+                else
+                        *p = '\0'; /* "PFX/manN/NAME.N" -> "PFX/manN" */
+
+                /* If link has slashes (however many), we go back *once*.
+                 * ".so zzz/ggg/page.3" does NOT go back two levels.
+                 */
                 if (strchr(linkname, '/')) {
+                        if (!p) { /* man_filename had no path */
+                                man_filename--; /* ".." */
+                                goto append_link;
+                        }
                         p = strrchr(man_filename, '/');
                         if (!p)
-                                goto ordinary_manpage;
-                        *p = '\0';
-                }
+                                man_filename = (char*)".." + 1; /* "manN" -> "." */
+                        else
+                                *p = '\0'; /* "PFX/manN" -> "PFX" */
+                } /* else (link has no slashes): will do "PFX/manN" -> "PFX/manN/link" */
 
                 /* Links do not have .gz extensions, even if manpage
                  * is compressed */
+ append_link:
                 man_filename = xasprintf("%s/%s", man_filename, linkname);
                 free(line);
                 /* Note: we leak "new" man_filename string as well... */
@@ -172,26 +184,26 @@ static int show_manpage(char *man_filename, int man, int level)
 #endif
 
 #if ENABLE_FEATURE_SEAMLESS_LZMA
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_XZ
         strcpy(ext, "xz");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_BZ2
         strcpy(ext, "bz2");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 #if ENABLE_FEATURE_SEAMLESS_GZ
         strcpy(ext, "gz");
-        if (run_pipe(filename_with_zext, man, level))
+        if (run_man_pipe(filename_with_zext, man, level))
                 return 1;
 #endif
 
-        return run_pipe(man_filename, man, level);
+        return run_man_pipe(man_filename, man, level);
 }
 
 static char **add_MANPATH(char **man_path_list, int *count_mp, char *path)