Merge branch 'hg/id-munging'

* hg/id-munging:
  convert: Keep foreign $Id$ on checkout.
  convert: Safer handling of $Id$ contraction.

convert.c

@@ -425,6 +425,8 @@ static int count_ident(const char *cp, unsigned long size)
 				cnt++;
 				break;
 			}
+			if (ch == '\n')
+				break;
 		}
 	}
 	return cnt;
@@ -455,6 +457,11 @@ static int ident_to_git(const char *path, const char *src, size_t len,
 			dollar = memchr(src + 3, '$', len - 3);
 			if (!dollar)
 				break;
+			if (memchr(src + 3, '\n', dollar - src - 3)) {
+				/* Line break before the next dollar. */
+				continue;
+			}
+
 			memcpy(dst, "Id$", 3);
 			dst += 3;
 			len -= dollar + 1 - src;
@@ -470,7 +477,7 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
                              struct strbuf *buf, int ident)
 {
 	unsigned char sha1[20];
-	char *to_free = NULL, *dollar;
+	char *to_free = NULL, *dollar, *spc;
 	int cnt;
 
 	if (!ident)
@@ -506,7 +513,10 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
 		} else if (src[2] == ':') {
 			/*
 			 * It's possible that an expanded Id has crept its way into the
-			 * repository, we cope with that by stripping the expansion out
+			 * repository, we cope with that by stripping the expansion out.
+			 * This is probably not a good idea, since it will cause changes
+			 * on checkout, which won't go away by stash, but let's keep it
+			 * for git-style ids.
 			 */
 			dollar = memchr(src + 3, '$', len - 3);
 			if (!dollar) {
@@ -514,6 +524,20 @@ static int ident_to_worktree(const char *path, const char *src, size_t len,
 				break;
 			}
 
+			if (memchr(src + 3, '\n', dollar - src - 3)) {
+				/* Line break before the next dollar. */
+				continue;
+			}
+
+			spc = memchr(src + 4, ' ', dollar - src - 4);
+			if (spc && spc < dollar-1) {
+				/* There are spaces in unexpected places.
+				 * This is probably an id from some other
+				 * versioning system. Keep it for now.
+				 */
+				continue;
+			}
+
 			len -= dollar + 1 - src;
 			src  = dollar + 1;
 		} else {

t/t0021-conversion.sh

@@ -65,17 +65,21 @@ test_expect_success expanded_in_repo '
 		echo "\$Id:NoSpaceAtFront \$"
 		echo "\$Id:NoSpaceAtEitherEnd\$"
 		echo "\$Id: NoTerminatingSymbol"
+		echo "\$Id: Foreign Commit With Spaces \$"
+		echo "\$Id: NoTerminatingSymbolAtEOF"
 	} > expanded-keywords &&
 
 	{
 		echo "File with expanded keywords"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
-		echo "\$Id: 4f21723e7b15065df7de95bd46c8ba6fb1818f4c \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
+		echo "\$Id: fd0478f5f1486f3d5177d4c3f6eb2765e8fc56b9 \$"
 		echo "\$Id: NoTerminatingSymbol"
+		echo "\$Id: Foreign Commit With Spaces \$"
+		echo "\$Id: NoTerminatingSymbolAtEOF"
 	} > expected-output &&
 
 	git add expanded-keywords &&