ash: fix for last commit

[oweals/busybox.git] / editors / patch.c

diff --git a/editors/patch.c b/editors/patch.c
index 13785ef460ab45821ac6451119255707709b1a21..81316fae3e72dc91c09ba7b1b6d7eb0a6f77af9a 100644 (file)
--- a/editors/patch.c
+++ b/editors/patch.c
@@ -23,10 +23,10 @@
  */
 
 //config:config PATCH
-//config:      bool "patch"
+//config:      bool "patch (9.1 kb)"
 //config:      default y
 //config:      help
-//config:        Apply a unified diff formatted patch.
+//config:      Apply a unified diff formatted patch.
 
 //applet:IF_PATCH(APPLET(patch, BB_DIR_USR_BIN, BB_SUID_DROP))
 
@@ -247,7 +247,7 @@ static int apply_one_hunk(void)
                // Figure out which line of hunk to compare with next.  (Skip lines
                // of the hunk we'd be adding.)
                while (plist && *plist->data == "+-"[reverse]) {
-                       if (data && !strcmp(data, plist->data+1)) {
+                       if (data && strcmp(data, plist->data+1) == 0) {
                                if (!backwarn) {
                                        backwarn = TT.linenum;
                                        if (option_mask32 & FLAG_IGNORE) {
@@ -290,12 +290,24 @@ static int apply_one_hunk(void)
                // out of buffer.
 
                for (;;) {
+                       while (plist && *plist->data == "+-"[reverse]) {
+                               if (strcmp(check->data, plist->data+1) == 0
+                                && !backwarn
+                               ) {
+                                       backwarn = TT.linenum;
+                                       if (option_mask32 & FLAG_IGNORE) {
+                                               dummy_revert = 1;
+                                               reverse ^= 1;
+                                       }
+                               }
+                               plist = plist->next;
+                       }
                        if (!plist || strcmp(check->data, plist->data+1)) {
                                // Match failed.  Write out first line of buffered data and
                                // recheck remaining buffered data for a new match.
 
                                if (PATCH_DEBUG)
-                                       fdprintf(2, "NOT: %s\n", plist->data);
+                                       fdprintf(2, "NOT: %s\n", plist ? plist->data : "EOF");
 
                                TT.state = 3;
                                check = buf;
@@ -345,6 +357,8 @@ done:
 // state 1: Found +++ file indicator, look for @@
 // state 2: In hunk: counting initial context lines
 // state 3: In hunk: getting body
+// Like GNU patch, we don't require a --- line before the +++, and
+// also allow the --- after the +++ line.
 
 int patch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int patch_main(int argc UNUSED_PARAM, char **argv)
@@ -370,10 +384,6 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                        xmove_fd(xopen_stdin(argv[1]), STDIN_FILENO);
                }
        }
-       if (argv[0]) {
-               oldname = xstrdup(argv[0]);
-               newname = xstrdup(argv[0]);
-       }
 
        // Loop through the lines in the patch
        for(;;) {
@@ -412,7 +422,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                }
 
                // Open a new file?
-               if (!strncmp("--- ", patchline, 4) || !strncmp("+++ ", patchline, 4)) {
+               if (is_prefixed_with(patchline, "--- ") || is_prefixed_with(patchline, "+++ ")) {
                        char *s, **name = reverse ? &newname : &oldname;
                        int i;
 
@@ -444,7 +454,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
 
                // Start a new hunk?  Usually @@ -oldline,oldlen +newline,newlen @@
                // but a missing ,value means the value is 1.
-               } else if (state == 1 && !strncmp("@@ -", patchline, 4)) {
+               } else if (state == 1 && is_prefixed_with(patchline, "@@ -")) {
                        int i;
                        char *s = patchline+4;
 
@@ -462,6 +472,14 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                        TT.context = 0;
                        state = 2;
 
+                       // If the --- line is missing or malformed, either oldname
+                       // or (for -R) newname could be NULL -- but not both.  Like
+                       // GNU patch, proceed based on the +++ line, and avoid SEGVs.
+                       if (!oldname)
+                               oldname = xstrdup("MISSING_FILENAME");
+                       if (!newname)
+                               newname = xstrdup("MISSING_FILENAME");
+
                        // If this is the first hunk, open the file.
                        if (TT.filein == -1) {
                                int oldsum, newsum, empty = 0;
@@ -474,12 +492,12 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
 
                                // We're deleting oldname if new file is /dev/null (before -p)
                                // or if new hunk is empty (zero context) after patching
-                               if (!strcmp(name, "/dev/null") || !(reverse ? oldsum : newsum)) {
+                               if (strcmp(name, "/dev/null") == 0 || !(reverse ? oldsum : newsum)) {
                                        name = reverse ? newname : oldname;
-                                       empty++;
+                                       empty = 1;
                                }
 
-                               // handle -p path truncation.
+                               // Handle -p path truncation.
                                for (i = 0, s = name; *s;) {
                                        if ((option_mask32 & FLAG_PATHLEN) && TT.prefix == i)
                                                break;
@@ -490,6 +508,9 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                        i++;
                                        name = s;
                                }
+                               // If "patch FILE_TO_PATCH", completely ignore name from patch
+                               if (argv[0])
+                                       name = argv[0];
 
                                if (empty) {
                                        // File is empty after the patches have been applied
@@ -507,7 +528,7 @@ int patch_main(int argc UNUSED_PARAM, char **argv)
                                        struct stat statbuf;
 
                                        // If the old file was null, we're creating a new one.
-                                       if (!strcmp(oldname, "/dev/null") || !oldsum) {
+                                       if (strcmp(oldname, "/dev/null") == 0 || !oldsum) {
                                                printf("creating %s\n", name);
                                                s = strrchr(name, '/');
                                                if (s) {