preparatory cleanups for seamless uncompression improvements

unpack_gz_stream_with_info: fix buggy error check
man: fix possible accesses past the end of a string
move seamless uncompression helpers from read_printf.c to open_transformer.c

function                                             old     new   delta
show_manpage                                         153     212     +59
unpack_gz_stream_with_info                           520     539     +19

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

1 files changed, 18 insertions, 23 deletions

diff --git a/miscutils/man.c b/miscutils/man.c
index 3bf7e84b6..611466349 100644
--- a/miscutils/man.c
+++ b/miscutils/man.c
@@ -30,16 +30,6 @@ echo ".pl \n(nlu+10"
 
 */
 
-#if ENABLE_FEATURE_SEAMLESS_LZMA
-#define Z_SUFFIX ".lzma"
-#elif ENABLE_FEATURE_SEAMLESS_BZ2
-#define Z_SUFFIX ".bz2"
-#elif ENABLE_FEATURE_SEAMLESS_GZ
-#define Z_SUFFIX ".gz"
-#else
-#define Z_SUFFIX ""
-#endif
-
 static int show_manpage(const char *pager, char *man_filename, int man, int level);
 
 static int run_pipe(const char *pager, char *man_filename, int man, int level)
@@ -102,7 +92,7 @@ static int run_pipe(const char *pager, char *man_filename, int man, int level)
 
                 /* Links do not have .gz extensions, even if manpage
                  * is compressed */
-                man_filename = xasprintf("%s/%s" Z_SUFFIX, man_filename, linkname);
+                man_filename = xasprintf("%s/%s", man_filename, linkname);
                 free(line);
                 /* Note: we leak "new" man_filename string as well... */
                 if (show_manpage(pager, man_filename, man, level + 1))
@@ -124,32 +114,37 @@ static int run_pipe(const char *pager, char *man_filename, int man, int level)
         return 1;
 }
 
-/* man_filename is of the form "/dir/dir/dir/name.s" Z_SUFFIX */
+/* man_filename is of the form "/dir/dir/dir/name.s" */
 static int show_manpage(const char *pager, char *man_filename, int man, int level)
 {
+#if SEAMLESS_COMPRESSION
+        /* We leak this allocation... */
+        char *filename_with_zext = xasprintf("%s.lzma", man_filename);
+        char *ext = strrchr(filename_with_zext, '.') + 1;
+#endif
+
 #if ENABLE_FEATURE_SEAMLESS_LZMA
+        if (run_pipe(pager, filename_with_zext, man, level))
+                return 1;
+#endif
+#if ENABLE_FEATURE_SEAMLESS_XZ
+        strcpy(ext, "xz");
         if (run_pipe(pager, man_filename, man, level))
                 return 1;
 #endif
-
 #if ENABLE_FEATURE_SEAMLESS_BZ2
-#if ENABLE_FEATURE_SEAMLESS_LZMA
-        strcpy(strrchr(man_filename, '.') + 1, "bz2");
-#endif
+        strcpy(ext, "bz2");
         if (run_pipe(pager, man_filename, man, level))
                 return 1;
 #endif
-
 #if ENABLE_FEATURE_SEAMLESS_GZ
-#if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2
-        strcpy(strrchr(man_filename, '.') + 1, "gz");
-#endif
+        strcpy(ext, "gz");
         if (run_pipe(pager, man_filename, man, level))
                 return 1;
 #endif
 
-#if ENABLE_FEATURE_SEAMLESS_LZMA || ENABLE_FEATURE_SEAMLESS_BZ2 || ENABLE_FEATURE_SEAMLESS_GZ
-        *strrchr(man_filename, '.') = '\0';
+#if SEAMLESS_COMPRESSION
+        ext[-1] = '\0';
 #endif
         if (run_pipe(pager, man_filename, man, level))
                 return 1;
@@ -262,7 +257,7 @@ int man_main(int argc UNUSED_PARAM, char **argv)
                                 /* Search for cat, then man page */
                                 while (cat0man1 < 2) {
                                         int found_here;
-                                        man_filename = xasprintf("%s/%s%.*s/%s.%.*s" Z_SUFFIX,
+                                        man_filename = xasprintf("%s/%s%.*s/%s.%.*s",
                                                         cur_path,
                                                         "cat\0man" + (cat0man1 * 4),
                                                         sect_len, cur_sect,