Superficial changes to make the exclude/include code easier to understand

2 files changed, 68 insertions, 44 deletions

diff --git a/archival/tar.c b/archival/tar.c
index ea0247e56..bb66d40cc 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -513,25 +513,30 @@ void append_file_to_list(char *filename, char ***name_list, int *num_of_entries)
                 if (line_ptr) {
                         *line_ptr = '\0';
                 }
-                *name_list = realloc(*name_list, sizeof(char *) * (*num_of_entries + 1));
+                *name_list = realloc(*name_list, sizeof(char *) * (*num_of_entries + 2));
                 (*name_list)[*num_of_entries] = xstrdup(line);
                 (*num_of_entries)++;
                 free(line);
         }
         fclose(src_stream);
+        (*name_list)[*num_of_entries] = NULL;
 }
 
 #ifdef BB_FEATURE_TAR_EXCLUDE
-char **merge_list(char **include_list, char **exclude_list)
+/*
+ * Create a list of names that are in the include list AND NOT in the exclude lists
+ */
+char **list_and_not_list(char **include_list, char **exclude_list)
 {
         char **new_include_list = NULL;
         int new_include_count = 0;
         int include_count = 0;
         int exclude_count;
 
-        if (include_list == NULL)
-                return exclude_list;
-
+        if (include_list == NULL) {
+                return(NULL);
+        }
+        
         while (include_list[include_count] != NULL) {
                 int found = FALSE;
                 exclude_count = 0;
@@ -547,12 +552,12 @@ char **merge_list(char **include_list, char **exclude_list)
                         new_include_list = realloc(new_include_list, sizeof(char *) * (include_count + 2));
                         new_include_list[new_include_count] = include_list[include_count];
                         new_include_count++;
-                        new_include_list[new_include_count] = NULL;
                 } else {
                         free(include_list[include_count]);
                 }
                 include_count++;
         }
+        new_include_list[new_include_count] = NULL;
         return(new_include_list);
 }
 #endif
@@ -572,12 +577,13 @@ int tar_main(int argc, char **argv)
 
 #ifdef BB_FEATURE_TAR_EXCLUDE
         char **exclude_list = NULL;
-        int exclude_count = 0;
+        int exclude_list_count = 0;
 #endif
 
         FILE *src_stream = NULL;
         FILE *uncompressed_stream = NULL;
         char **include_list = NULL;
+        char **the_real_list = NULL;
         char *src_filename = NULL;
         char *dst_prefix = NULL;
         char *file_list_name = NULL;
@@ -585,7 +591,7 @@ int tar_main(int argc, char **argv)
         unsigned short untar_funct = 0;
         unsigned short untar_funct_required = 0;
         unsigned short extract_function = 0;
-        int include_count = 0;
+        int include_list_count = 0;
         int gunzip_pid;
         int gz_fd = 0;
 
@@ -621,13 +627,13 @@ int tar_main(int argc, char **argv)
                 /* Exclude or Include files listed in <filename>*/
 #ifdef BB_FEATURE_TAR_EXCLUDE
                 case 'X':
-                        append_file_to_list(optarg, &exclude_list, &exclude_count);
-                        exclude_list[exclude_count] = NULL;     
+                        append_file_to_list(optarg, &exclude_list, &exclude_list_count);
+                        exclude_list[exclude_list_count] = NULL;        
                         break;
 #endif
                 case 'T':
                         // by default a list is an include list
-                        append_file_to_list(optarg, &include_list, &include_count);
+                        append_file_to_list(optarg, &include_list, &include_list_count);
                         break;
 
                 case 'C':       // Change to dir <optarg>
@@ -677,23 +683,29 @@ int tar_main(int argc, char **argv)
 
         /* Setup an array of filenames to work with */
         while (optind < argc) {
-                include_list = realloc(include_list, sizeof(char *) * (include_count + 2));
-                include_list[include_count] = xstrdup(argv[optind]);
-                include_count++;
+                include_list = realloc(include_list, sizeof(char *) * (include_list_count + 2));
+                include_list[include_list_count] = xstrdup(argv[optind]);
+                include_list_count++;
                 optind++;
-                include_list[include_count] = NULL;
+                include_list[include_list_count] = NULL;
         }
 
+        /* By default the include list is the list we act on */
+        the_real_list = include_list;
+
 #ifdef BB_FEATURE_TAR_EXCLUDE
-        /* Remove excluded files from the include list */
         if (exclude_list != NULL) {
-                /* If both an exclude and include file list were present then
-                 * it's an exclude from include list only, if not it's really an
-                 * exclude list (and a poor choice of variable names) */
                 if (include_list == NULL) {
+                        /* the_real_list is an exclude list */
                         extract_function |= extract_exclude_list;
+                        the_real_list = exclude_list;
+                } else {
+                        /* Both an exclude and include file list was present,
+                         * its an exclude from include list only.
+                         * Remove excluded files from the include list
+                         */
+                        the_real_list = list_and_not_list(include_list, exclude_list);
                 }
-                include_list = merge_list(include_list, exclude_list);
         }
 #endif
 
@@ -717,7 +729,7 @@ int tar_main(int argc, char **argv)
                         uncompressed_stream = src_stream;
                 
                 /* extract or list archive */
-                unarchive(uncompressed_stream, stdout, &get_header_tar, extract_function, dst_prefix, include_list);
+                unarchive(uncompressed_stream, stdout, &get_header_tar, extract_function, dst_prefix, the_real_list);
                 fclose(uncompressed_stream);
         }
 #ifdef BB_FEATURE_TAR_CREATE
@@ -733,7 +745,7 @@ int tar_main(int argc, char **argv)
                 if (extract_function & extract_verbose_list) {
                         verboseFlag = TRUE;
                 }
-                writeTarFile(src_filename, verboseFlag, &argv[argc - 1], include_list);
+                writeTarFile(src_filename, verboseFlag, &argv[argc - 1], the_real_list);
         }
 #endif // BB_FEATURE_TAR_CREATE
 
diff --git a/tar.c b/tar.c
index ea0247e56..bb66d40cc 100644
--- a/tar.c
+++ b/tar.c
@@ -513,25 +513,30 @@ void append_file_to_list(char *filename, char ***name_list, int *num_of_entries)
                 if (line_ptr) {
                         *line_ptr = '\0';
                 }
-                *name_list = realloc(*name_list, sizeof(char *) * (*num_of_entries + 1));
+                *name_list = realloc(*name_list, sizeof(char *) * (*num_of_entries + 2));
                 (*name_list)[*num_of_entries] = xstrdup(line);
                 (*num_of_entries)++;
                 free(line);
         }
         fclose(src_stream);
+        (*name_list)[*num_of_entries] = NULL;
 }
 
 #ifdef BB_FEATURE_TAR_EXCLUDE
-char **merge_list(char **include_list, char **exclude_list)
+/*
+ * Create a list of names that are in the include list AND NOT in the exclude lists
+ */
+char **list_and_not_list(char **include_list, char **exclude_list)
 {
         char **new_include_list = NULL;
         int new_include_count = 0;
         int include_count = 0;
         int exclude_count;
 
-        if (include_list == NULL)
-                return exclude_list;
-
+        if (include_list == NULL) {
+                return(NULL);
+        }
+        
         while (include_list[include_count] != NULL) {
                 int found = FALSE;
                 exclude_count = 0;
@@ -547,12 +552,12 @@ char **merge_list(char **include_list, char **exclude_list)
                         new_include_list = realloc(new_include_list, sizeof(char *) * (include_count + 2));
                         new_include_list[new_include_count] = include_list[include_count];
                         new_include_count++;
-                        new_include_list[new_include_count] = NULL;
                 } else {
                         free(include_list[include_count]);
                 }
                 include_count++;
         }
+        new_include_list[new_include_count] = NULL;
         return(new_include_list);
 }
 #endif
@@ -572,12 +577,13 @@ int tar_main(int argc, char **argv)
 
 #ifdef BB_FEATURE_TAR_EXCLUDE
         char **exclude_list = NULL;
-        int exclude_count = 0;
+        int exclude_list_count = 0;
 #endif
 
         FILE *src_stream = NULL;
         FILE *uncompressed_stream = NULL;
         char **include_list = NULL;
+        char **the_real_list = NULL;
         char *src_filename = NULL;
         char *dst_prefix = NULL;
         char *file_list_name = NULL;
@@ -585,7 +591,7 @@ int tar_main(int argc, char **argv)
         unsigned short untar_funct = 0;
         unsigned short untar_funct_required = 0;
         unsigned short extract_function = 0;
-        int include_count = 0;
+        int include_list_count = 0;
         int gunzip_pid;
         int gz_fd = 0;
 
@@ -621,13 +627,13 @@ int tar_main(int argc, char **argv)
                 /* Exclude or Include files listed in <filename>*/
 #ifdef BB_FEATURE_TAR_EXCLUDE
                 case 'X':
-                        append_file_to_list(optarg, &exclude_list, &exclude_count);
-                        exclude_list[exclude_count] = NULL;     
+                        append_file_to_list(optarg, &exclude_list, &exclude_list_count);
+                        exclude_list[exclude_list_count] = NULL;        
                         break;
 #endif
                 case 'T':
                         // by default a list is an include list
-                        append_file_to_list(optarg, &include_list, &include_count);
+                        append_file_to_list(optarg, &include_list, &include_list_count);
                         break;
 
                 case 'C':       // Change to dir <optarg>
@@ -677,23 +683,29 @@ int tar_main(int argc, char **argv)
 
         /* Setup an array of filenames to work with */
         while (optind < argc) {
-                include_list = realloc(include_list, sizeof(char *) * (include_count + 2));
-                include_list[include_count] = xstrdup(argv[optind]);
-                include_count++;
+                include_list = realloc(include_list, sizeof(char *) * (include_list_count + 2));
+                include_list[include_list_count] = xstrdup(argv[optind]);
+                include_list_count++;
                 optind++;
-                include_list[include_count] = NULL;
+                include_list[include_list_count] = NULL;
         }
 
+        /* By default the include list is the list we act on */
+        the_real_list = include_list;
+
 #ifdef BB_FEATURE_TAR_EXCLUDE
-        /* Remove excluded files from the include list */
         if (exclude_list != NULL) {
-                /* If both an exclude and include file list were present then
-                 * it's an exclude from include list only, if not it's really an
-                 * exclude list (and a poor choice of variable names) */
                 if (include_list == NULL) {
+                        /* the_real_list is an exclude list */
                         extract_function |= extract_exclude_list;
+                        the_real_list = exclude_list;
+                } else {
+                        /* Both an exclude and include file list was present,
+                         * its an exclude from include list only.
+                         * Remove excluded files from the include list
+                         */
+                        the_real_list = list_and_not_list(include_list, exclude_list);
                 }
-                include_list = merge_list(include_list, exclude_list);
         }
 #endif
 
@@ -717,7 +729,7 @@ int tar_main(int argc, char **argv)
                         uncompressed_stream = src_stream;
                 
                 /* extract or list archive */
-                unarchive(uncompressed_stream, stdout, &get_header_tar, extract_function, dst_prefix, include_list);
+                unarchive(uncompressed_stream, stdout, &get_header_tar, extract_function, dst_prefix, the_real_list);
                 fclose(uncompressed_stream);
         }
 #ifdef BB_FEATURE_TAR_CREATE
@@ -733,7 +745,7 @@ int tar_main(int argc, char **argv)
                 if (extract_function & extract_verbose_list) {
                         verboseFlag = TRUE;
                 }
-                writeTarFile(src_filename, verboseFlag, &argv[argc - 1], include_list);
+                writeTarFile(src_filename, verboseFlag, &argv[argc - 1], the_real_list);
         }
 #endif // BB_FEATURE_TAR_CREATE