EAPI 6: Explain eapply behavior.

Bug: 463768

1 files changed, 35 insertions, 2 deletions

diff --git a/pkg-mgr-commands.tex b/pkg-mgr-commands.tex
index 28a96b0..89c00ff 100644
--- a/pkg-mgr-commands.tex
+++ b/pkg-mgr-commands.tex
@@ -148,14 +148,47 @@ These commands are used during the \t{src\_prepare} phase to apply patches to th
 Ebuilds must not run any of these commands once the current phase function has returned.
 
 \begin{description}
-\item[eapply] \featurelabel{eapply}
+\item[eapply] \featurelabel{eapply} Takes zero or more GNU patch options, followed by one or more
+    file or directory paths. Processes options and applies all patches found in specified locations
+    according to Algorithm~\ref{alg:eapply}. If applying the patches fails, it aborts the build
+    using \t{die}, unless run using \t{nonfatal}, in which case it returns non-zero exit status.
     Only available in EAPIs listed in table~\ref{tab:patch-commands} as supporting \t{eapply}.
 \end{description}
 
 \begin{algorithm}
 \caption{eapply logic} \label{alg:eapply}
 \begin{algorithmic}[1]
-\STATE \COMMENT{WORK IN PROGRESS}
+\IF{any parameter is equal to \t{"-{}-"}}
+    \STATE collect all parameters before the first \t{"-{}-"} in the \t{options} array
+    \STATE collect all parameters after the first \t{"-{}-"} in the \t{files} array
+\ELSIF{any parameter that begins with a hyphen follows one that does not}
+    \STATE abort the build process with an error
+\ELSE
+    \STATE collect all parameters beginning with a hyphen in the \t{options} array
+    \STATE collect all remaining parameters in the \t{files} array
+\ENDIF
+\IF{the \t{files} array is empty}
+    \STATE abort the build process with an error
+\ENDIF
+\FORALL{\t{x} in the \t{files} array}
+    \IF{\t{\$x} is a directory}
+        \IF{\NOT any files match \t{\$x/*.diff} or \t{\$x/*.patch}}
+            \STATE abort the build process with an error
+        \ENDIF
+        \FORALL{files \t{f} matching \t{\$x/*.diff} or \t{\$x/*.patch}, sorted in POSIX locale}
+            \STATE call \t{patch -p1 -f -g0 -{}-no-backup-if-mismatch "\$\{options[@]\}" < "\$f"}
+            \IF{child process returned with non-zero exit status}
+                \RETURN immediately with that status
+            \ENDIF
+        \ENDFOR
+    \ELSE
+        \STATE call \t{patch -p1 -f -g0 -{}-no-backup-if-mismatch "\$\{options[@]\}" < "\$x"}
+        \IF{child process returned with non-zero exit status}
+            \RETURN immediately with that status
+        \ENDIF
+    \ENDIF
+\ENDFOR
+\RETURN shell true (0)
 \end{algorithmic}
 \end{algorithm}